Atmel QTouch Safety Library Peripheral Touch Controller USER GUIDE Description Atmel QTouch Peripheral Touch Controller (PTC) offers built-in hardware for buttons, sliders, and wheels. PTC supports both mutual and self capacitance measurement without the need for any external component. It offers superb sensitivity and noise tolerance, as well as self-calibration and minimizes the sensitivity tuning effort by the user. The PTC is intended for acquiring capacitive touch sensor signals. The external capacitive touch sensor is typically formed on a PCB, and the sensor electrodes are connected to the analog charge integrator of the PTC using the device I/O pins. The PTC supports mutual capacitance sensors organized as capacitive touch matrices in different X-Y configurations, including Indium Tin Oxide (ITO) sensor grids. In mutual capacitance mode, the PTC requires one pin per X line (drive line) and one pin per Y line (sense line). In self capacitance mode, the PTC requires only one pin with a Y-line driver for each self-capacitance sensor. The PTC supports two sets of libraries, the QTouch Library and the QTouch Safety Library. The QTouch Library supports both mutual and self capacitance methods. The QTouch Safety Library is available for both GCC and IAR. The QTouch Safety Library also supports both the mutual capacitance method and self capacitance method along with the additional safety features. Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 1. Development Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 1.1 2. QTouch Safety Library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 2.11 2.12 2.13 2.14 2.15 2.16 2.17 2.18 3. Device Variants Supported . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 API Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Sequence of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Program Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Configuration Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2.4.1 Pin Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 2.4.2 Sensor Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 2.4.3 Acquisition Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 2.4.4 Sensor Global Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 2.4.5 Common Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 2.4.6 Noise Immunity Global Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 2.4.7 Noise Immunity Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 2.4.8 Sensor Lockout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 2.4.9 Frequency Auto Tune . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Touch Library Error Reporting Mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Touch Library Program Counter Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 2.6.1 Logical Program Flow Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 2.6.2 Program Counter Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 CRC on Touch Input Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Double Inverse Memory Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 2.8.1 Application to Touch Library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 2.8.2 Touch Library to Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Application Burst Again Mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Memory Requirement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 2.10.1 Memory Requirement for IAR Safety library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 API Execution Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 2.11.1 Mutual Capacitance API Execution Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 2.11.2 Self Capacitance API Execution Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Error Interpretation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 2.12.1 Error Codes Returned Synchronously . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 2.12.2 Error Codes Returned Through Callback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Data and Function Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Moisture Tolerance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 2.14.1 Moisture Tolerance Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 2.14.2 Multi-touch Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Quick Re-burst . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 2.15.1 Synchronizing Quick Re-burst and Application Burst again . . . . . . . . . . . . . . . . . . . . . . . 48 Reading Sensor States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Touch Library Suspend Resume Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Drifting on Disabled Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 QTouch Safety Library API . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 3.1 3.2 3.3 Typedefs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 Macros. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 3.2.1 Touch Library Acquisition Status Bit Fields. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 3.2.2 Sensor State Configurations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 Enumerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 3.3.1 Touch Library GAIN Setting(tag_gain_t) . . . . . . . . . . . . . . . . 53 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 3 3.4 3.5 3.6 4 3.3.2 Filter Level Setting (tag_filter_level_t) . . . . . . . . . . . . . . . 53 3.3.3 Touch Library AUTO OS Setting (tag_auto_os_t) . . . . . . . . . . . . 53 3.3.4 Library Error Code (tag_touch_ret_t) . . . . . . . . . . . . . . . . 54 3.3.5 Sensor Channel (tag_channel_t) . . . . . . . . . . . . . . . . . . 55 3.3.6 Touch Library State (tag_touch_lib_state_t) . . . . . . . . . . . . 55 3.3.7 Sensor Type (tag_sensor_type_t) . . . . . . . . . . . . . . . . . 55 3.3.8 Touch Library Acquisition Mode (tag_touch_acq_mode_t) . . . . . . . . . 55 3.3.9 AKS Group (tag_aks_group_t) . . . . . . . . . . . . . . . . . . . 56 3.3.10 Channel Gain Setting (tag_gain_t) . . . . . . . . . . . . . . . . . . 56 3.3.11 Sensor Recalibration Threshold (tag_recal_threshold_t) . . . . . . . . 57 3.3.12 Rotor Slider Resolution (tag_resolution_t) . . . . . . . . . . . . . . 57 3.3.13 Auto Tune Setting (tag_auto_tune_type_t) . . . . . . . . . . . . . . 57 3.3.14 PTC Clock Prescale Setting (tag_prsc_div_sel_t) . . . . . . . . . . . 58 3.3.15 PTC Series Resistor Setting (tag_rsel_val_t) . . . . . . . . . . . . . 58 3.3.16 PTC Acquisition Frequency Delay Setting (freq_hop_sel_t) . . . . . . . . 59 3.3.17 PTC Acquisition Frequency Mode Setting (tag_freq_mode_sel_t) . . . . . . 59 3.3.18 PTC Sensor Lockout Setting (nm_sensor_lockout_t) . . . . . . . . . . 60 3.3.19 Moisture Group Setting (moisture_grp_t) . . . . . . . . . . . . . . . 60 3.3.20 Multi-touch Group Setting (mltch_grp_t) . . . . . . . . . . . . . . . . 60 Data Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 3.4.1 Touch Library Configuration Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 3.4.2 Touch Library Safety Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 3.4.3 Touch Library Double Inverse Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 3.4.4 Touch Library Parameter Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 3.4.5 Touch Library Measurement Data Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 3.4.6 Touch Library Filter Data Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 3.4.7 Touch Library Time Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 3.4.8 Touch Library Info Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 3.4.9 Touch Library Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 Global Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 3.5.1 touch_lib_fault_test_status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 3.5.2 touch_error_app_cb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 3.5.3 touch_suspend_app_cb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 3.6.1 Touch Library Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 3.6.2 Touch Library Sensor Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 3.6.3 Touch Library Sensor Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 3.6.4 Touch Library Sensor Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 3.6.5 Touch Library Sensor Specific Touch Delta Read . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 3.6.6 Touch Library Sensor Specific Parameter Configuration Read-write . . . . . . . . . . . . . . . . 72 3.6.7 Touch Library Sensor Specific Acquisition Configuration Read-write . . . . . . . . . . . . . . . . 72 3.6.8 Touch Library Sensor Global Parameter Configuration Read-write . . . . . . . . . . . . . . . . . 73 3.6.9 Touch Library Info Read . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 3.6.10 Touch Library Program Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 3.6.11 Touch Library CRC Configuration Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 3.6.12 Touch Library Double Inverse check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 3.6.13 Touch Library Enable Disable Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 3.6.14 Touch Library Version Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 3.6.15 Touch Library Moisture Tolerance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 3.6.16 Touch PTC Peripheral Enable Disable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 3.6.17 Touch Library Suspend Resume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 3.6.18 4. FMEA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 4.1 4.2 4.3 4.4 4.5 4.6 5. Double Inverse Memory Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 4.1.1 Application to FMEA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 4.1.2 FMEA to Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 Memory Requirement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 4.2.1 Memory Requirement for IAR Library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 API Execution Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 4.3.1 Mutual Capacitance API Execution Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 4.3.2 Self Capacitance API Execution Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 Error Interpretation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 Data and Function Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 FMEA Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 FMEA API . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 5.1 5.2 5.3 5.4 5.5 5.6 6. Touch Library Re-Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 Typedefs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 Enumerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 5.2.1 sf_fmea_faults_t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 Data Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 5.3.1 sf_xxxxcap_fmea_open_test_config_t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 5.3.2 sf_xxxxcap_fmea_input_config_t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 5.3.3 sf_mutlcap_fmea_fault_report_t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 5.3.4 sf_selfcap_fmea_fault_report_t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 Global Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 5.4.1 sf_xxxxcap_fmea_fault_report_var . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 5.5.1 sf_xxxxcap_fmea_init . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 5.5.2 sf_xxxxcap_fmea_test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 5.5.3 sf_xxxcap_fmea_test_open_pins_per_channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 5.5.4 sf_xxxxcap_fmea_stop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 Macros. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 6.9 6.10 6.11 6.12 Relocating Touch Library and FMEA RAM Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 6.1.1 Modifying the IAR Linker File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 6.1.2 Modifying GCC Linker File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 API Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 Safety Firmware Action Upon Fault Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 System Action Upon Fault Detection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 Touch Library and FMEA Synchronization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 Safety Firmware Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 SAMDSafety Firmware Certification Scope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 Hazard Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 ASF Dependency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 Robustness and Tuning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 Standards compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 Safety Certification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 8. Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 5 Features Implements low-power, high-sensitivity, environmentally robust capacitive touch buttons, sliders, and wheels Parasitic capacitance compensation for mutual capacitance mode Adjustable gain for superior sensitivity Supports mutual capacitance and self capacitance sensing Zero drift over the temperature and VDD range Upto 256 channels in mutual-capacitance mode No need for temperature or VDD compensation Upto 16 channels in self-capacitance mode Hardware noise filtering and noise signal desynchronization for high conducted immunity Two pin per electrode in mutual capacitance mode - with no external components Supports moisture tolerance Atmel provided QTouch Safety Library firmware One pin per electrode in self capacitance mode Supports Sensor Enable and Disable at - with no external components Runtime Load compensating charge sensing Supports Quick Reburst Feature for Faster Response Time The following features are available only in the QTouch Safety Library: CRC protection Logical program flow sequence Memory protection using double inverse mechanism Library RAM relocation and Compile-time and Run-time check For more information about the capacitance related technological concepts, Refer Chapter 4 in Atmel QTouch Library Peripheral Touch Controller User Guide [42195] available at www.atmel.com. Product Support For assistance related to QTouch capacitive touch sensing software libraries and related issues, contact your local Atmel sales representative or log on to myAtmel Design Support portal to submit a support request or access a comprehensive knowledge base. If you don’t have a myAtmel account, please visit http://www.atmel.com/design-support/ to create a new account by clicking on “Create Account” in the myAtmel menu at the top of the page. Once logged in, you will be able to access the knowledge base, submit new support cases from the myAtmel page or review status of your ongoing cases. Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 7 1. Development Tools The following development tools are required for QTouch Safety Library development using SAMD20/SAMD21 devices: Development Environment: IAR Embedded Workbench for ARM 7.40.3.8938 for IAR Compiler Atmel Software Framework 3.26.0.1381. Atmel Studio 6.2.1563- Service Pack 2 for GCC Compiler 1.1 Device Variants Supported QTouch Safety Library for SAMDevices is available for the following device variants: Series Variant SAM D20 J Series ATSAMD20J18, ATSAMD20J17, ATSAMD20J16, ATSAMD20J15 SAM D20 G Series ATSAMD20G18, ATSAMD20G17, ATSAMD20G16, ATSAMD20G15, ATSAMD20G17U, ATSAMD20G18U SAM D20 E Series ATSAMD20E18, ATSAMD20E17, ATSAMD20E16, ATSAMD20E15 SAM D21 J Series ATSAMD21J18A, ATSAMD21J17A, ATSAMD21J16A, ATSAMD21J16B, ATSAMD21J15A, ATSAMD21J15B SAM D21 G Series ATSAMD21G18A, ATSAMD21G18AU, ATSAMD21G17A, ATSAMD21G17AU, ATSAMD21G16A, ATSAMD21G16B, ATSAMD21G15A, ATSAMD21G15B SAM D21 E Series ATSAMD21E18A, ATSAMD21E17A, ATSAMD21E16A, ATSAMD21E16B, ATSAMD21E16BU, ATSAMD21E15A, ATSAMD21E15B, ATSAMD21E15BU Note: PIN_PB04 is not supported for Touch operation in ATSAMD21G17AU, ATSAMD21G18AU devices. 8 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 2. QTouch Safety Library Atmel QTouch Safety Library makes it simple for developers to embed capacitive-touch button, slider, wheel functionality into general-purpose Atmel SAMD20/SAMD21 microcontroller applications. The royalty-free QTouch Safety Library provides library files for each device and supports different numbers of touch channels, enabling both flexibility and efficiency in touch applications. QTouch Safety Library can be used to develop single-chip solutions for many control applications, or to reduce chip count in more complex applications. Developers have the latitude to implement buttons, sliders, and wheels in a variety of combinations on a single interface. Figure 2-1. 2.1 Atmel QTouch Safety Library API Overview QTouch Safety Library API for PTC can be used for touch sensor pin configuration, acquisition parameter setting as well as periodic sensor data capture and status update operations. The QTouch Safety Library interfaces with the PTC module to perform the required actions. The PTC module interfaces with the external capacitive touch sensors and is capable of performing mutual and self capacitance method measurements. Note: From this section onwards, the program elements that are common to both mutual and self capacitance technologies are represented using XXXXCAP or xxxxcap. Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 9 For normal operation, it is sufficient to use the Regular APIs. The Helper APIs provides additional flexibility to the user application. The available APIs are listed in the following table. Table 2-1. Regular and Helper APIs Regular API Helper API touch_xxxxcap_sensors_init touch_xxxxcap_sensor_get_delta touch_xxxxcap_di_init touch_xxxxcap_sensor_update_config touch_xxxxcap_sensor_config touch_xxxxcap_sensor_get_config touch_xxxxcap_sensors_calibrate touch_xxxxcap_update_global_param touch_xxxxcap_sensors_measure touch_xxxxcap_sensors_deinit touch_xxxxcap_get_global_param touch_xxxxcap_update_acq_config touch_xxxxcap_get_acq_config touch_xxxxcap_get_libinfo touch_xxxxcap_calibrate_single_sensor touch_xxxxcap_sensor_disable touch_xxxxcap_sensor_reenable touch_lib_pc_test_magic_no_1 touch_lib_pc_test_magic_no_2 touch_lib_pc_test_magic_no_3 touch_lib_pc_test_magic_no_4 touch_calc_xxxcap_config_data_integrity touch_test_xxxcap_config_data_integrity touch_xxxxcap_cnfg_mois_mltchgrp touch_xxxxcap_cnfg_mois_threshold touch_xxxxcap_mois_tolrnce_enable touch_xxxxcap_mois_tolrnce_disable touch_library_get_version_info touch_disable_ptc touch_enable_ptc touch_suspend_ptc touch_resume_ptc 10 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 Figure 2-2. QTouch Safety Library Overview $WPHO6$0 +RVW$SSOLFDWLRQ 47RXFK /LEUDU\$3, 6HQVRU7RXFK6WDWXV 5RWRU6OLGHU3RVLWLRQ 6HQVRU&KDQQHO 3LQ&RQILJXUDWLRQ 6HQVRU3DUDPHWHU 6HWWLQJ 6HQVRU6WDWXV 3RVLWLRQ3RVW 3URFHVVLQJ 6HQVRU6HOI &DOLEUDWLRQ $GMDFHQW.H\ 6XSSUHVLRQ70 1RLVH&RXQWHU 0HDVXUH DQG 0RLVWXUH7ROHUDQFH 'HWHFW,QWHJUDWLRQ 0HFKDQLVP $XWR5H&DOLEUDWLRQ 3URJUDP37& UHJLVWHUV 5DZVHQVRUGDWD 6$037&0RGXOH *3,23LQV &DSDFLWLYH7RXFK%XWWRQ6OLGHUV:KHHO3UR[LPLW\6HQVRU 2.2 Sequence of Operation The application periodically initiates a touch measurement on either mutual capacitance or self capacitance sensors. At the end of each sensor measurement, the PTC module generates an end of conversion (EOC) interrupt. The touch measurement is performed sequentially until all the sensors are measured. Additional post-processing is performed on the measured sensor data to determine the touch status of the sensors (keys/rotor/slider) position. The post processing determines the position value of the sensors and the callback function is then triggered to indicate completion of measurement. The recommended sequence of operation facilitates the CPU to either sleep or perform other functions during touch sensor measurement. Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 11 Figure 2-3. 2.3 QTouch Application Sequence Program Flow Before using the QTouch Safety Library API, configure the PTC module clock generator source. The PTC module clock can be generated using one of the eight generic clock generators (GCLK0-GCLK7). Configure the corresponding generic clock multiplexer such that the PTC module clock is set between 400 kHz and 4 MHz. The touch_xxxxcap_sensors_init API initializes the QTouch Safety Library as well as the PTC module. Additionally, it initializes the capacitance method specific pin, register, and global sensor configuration. The touch_xxxxcap_di_init API initializes the memory for different pointers in the touch_lib_xxxcap_param_safety structure. The touch_xxxxcap_sensor_config API configures the individual sensor. The sensor specific configuration parameters can be provided as input arguments to this API. The touch_xxxxcap_sensors_calibrate API calibrates all the configured sensors and prepares the sensors for normal operation. The auto tuning type parameter is provided as input argument to this API. The touch_xxxxcap_sensors_measure API initiates a touch measurement on all the configured sensors. The sequence of the mandatory APIs are depicted in the following illustration. 12 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 Figure 2-4. API Usage touch_xxxxcap_sensors_init() touch_xxxxcap_di_init() Configure multiple Touch sensors touch_xxxxcap_sensors_config() touch_xxxxcap_sensors_calibrate() Calibration starts when first time call to measure sensors API after sensors calibrate API. touch_xxxxcap_sensors_measure(NO RMAL_ACQ_MODE) PTC ISR (Sensors Calibration) filter_callback(), if enabled measure_complete_callback(), measured data and Touch Status Host Application code/ SLEEP If Library Burst Again Flag set to 1 internally No Is Calibration completed? Subsequent calls to measure sensors API after calibration will perform normal measurement. time_to_measure_touch Yes touch_xxxxcap_sensors_measure(NO RMAL_ACQ_MODE) Yes PTC ISR (Normal measurement) Call in loop filter_callback(), if enabled measure_complete_callback(), measured data and Touch Status Application wants immediate measurement No Host Application code/ SLEEP For configuring multiple sensors, touch_xxxxcap_config_sensor must be called every time to configure each sensor. 2.4 Configuration Parameters The following parameters are available in the QTouch Safety Library for configuring capacitance. Table 2-2. Configuration Parameters for Mutual and Self capacitance Methods Parameter Pin Configuration Sensor Configuration Parameter Macros Description DEF_MUTLCAP_NODES Number of Mutual Capacitance nodes. DEF_SELFCAP_LINES Number of Self Capacitance lines. DEF_XXXXCAP_NUM_CHANNELS Number of Channels. DEF_XXXXCAP_NUM_SENSORS Number of Sensors. DEF_XXXXCAP_NUM_ROTORS_SLIDERS Number of Rotor/Sliders. Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 13 Table 2-2. Configuration Parameters for Mutual and Self capacitance Methods Parameter Acquisition Parameters 14 Parameter Macros Description DEF_XXXXCAP_FILTER_LEVEL_PER_NODE The filter level setting controls the number of samples collected to resolve each acquisition. This is applicable for individual channel. DEF_XXXXCAP_GAIN_PER_NODE Gain is applied for an individual channel to allow a scaling-up of the touch delta. DEF_XXXXCAP_AUTO_OS_PER_NODE Auto oversample controls the automatic oversampling of sensor channels when unstable signals are detected. This is applicable for individual channel. DEF_XXXXCAP_FREQ_MODE Frequency mode setting allows users to configure the bursting waveform characteristics to get better noise performance for the system. DEF_XXXXCAP_CLK_PRESCALE_PER_NODE This method is used to select the PTC prescaler. This is applicable for individual channel. DEF_XXXXCAP_SENSE_RESISTOR_PER_NO DE This method is used to select the sense resistor value. This is applicable for individual channel. DEF_XXXXCAP_CC_CAL_CLK_PRESCALE_P ER_NODE This method is used to select the PTC prescalar for CC calibration. This is applicable for individual channel. DEF_XXXXCAP_CC_CAL_SENSE_RESISTOR _PER_NODE This method is used to select the sense resistor for CC calibration. This is applicable for individual channel. DEF_XXXXCAP_HOP_FREQS Frequency hops to be performed. Maximum three frequency hops is possible. Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 Table 2-2. Configuration Parameters for Mutual and Self capacitance Methods Parameter Sensor Global Parameters Parameter Macros Description Capacitance sensor detect integration (DI) limit. DEF_XXXXCAP_DI Range: 0u to 255u. DEF_XXXXCAP_TCH_DRIFT_RATE Capacitance sensor towards touch drift rate. Range: 1u to 127u. DEF_XXXXCAP_ATCH_DRIFT_RATE Capacitance sensor away from touch drift rate. Range: 1u to 127u. DEF_XXXXCAP_MAX_ON_DURATION Capacitance sensor maximum ON time duration. Range: 0u to 255u. DEF_XXXXCAP_DRIFT_HOLD_TIME Capacitance Sensor drift hold time. Range: 1u to 255u. DEF_XXXXCAP_ATCH_RECAL_DELAY Capacitance sensor away from touch recalibration delay. Range: 0u to 255u. Specifying a value of 0u would disable the away from touch recalibration feature. DEF_XXXXCAP_ATCH_RECAL_THRESHOLD Capacitance sensor away from touch recalibration threshold. DEF_XXXXCAP_CAL_SEQ1_COUNT Software calibration sequence counter 1. DEF_XXXXCAP_CAL_SEQ2_COUNT Software calibration sequence counter 2. DEF_XXXXCAP_NOISE_MEAS_SIGNAL_STA BILITY_LIMIT Defines the stability of the signals for noise measurement. Range: 1u to 1000u. This parameter is used to select the noise limit value to trigger sensor lockout functionality. DEF_XXXXCAP_NOISE_LIMIT Range: 1u to 255u. Sensor Global Parameters This parameter is used to select the lockout functionality method. DEF_XXXXCAP_LOCKOUT_SEL Range: 0u to 2u. DEF_XXXXCAP_LOCKOUT_CNTDOWN Defines the number of measurements after which the sensor is unlocked for touch detection. Range: 1u to 255u. DEF_XXXXCAP_FREQ_AUTO_TUNE_SIGNAL _STABILITY_LIMIT Defines the stability limit of signals for frequency auto tune decision making. Range: 1u to 1000u. DEF_XXXXCAP_FREQ_AUTO_TUNE_IN_CNT This parameter is used to trigger the frequency auto tune. Range: 1u to 255u. Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 15 Table 2-2. Configuration Parameters for Mutual and Self capacitance Methods Parameter Common Parameters Parameter Macros Description DEF_TOUCH_MEASUREMENT_PERIOD_MS User for Touch measurement periodicity. DEF_TOUCH_PTC_ISR_LVL PTC Module interrupt level. DEF_XXXXCAP_NOISE_MEAS_ENABLE This parameter is used to enable or disable the noise measurement. Range: 0 or 1. DEF_XXXXCAP_FREQ_AUTO_TUNE_ENABLE This parameter is used to enable and disable the frequency auto tune functionality. Range: 0 or 1. DEF_XXXXCAP_NOISE_MEAS_BUFFER_CNT This parameter is used to select the buffer count for noise measurement buffer. Range: 3 to 10. Moisture Tolerance and Quick re-burst Parameters 2.4.1 DEF_XXXXCAP_NUM_MOIS_GROUPS This parameter is used to configure the number of moisture groups. DEF_XXXXCAP_MOIS_TOLERANCE_ENABLE This parameter is used to enable or disable the Moisture tolerance feature. DEF_XXXXCAP_QUICK_REBURST_ENABLE This parameter id used to enable or disable the Quick re-burst feature. Pin Configuration 2.4.1.1 Mutual Capacitance Mutual capacitance method uses a pair of sensing electrodes for each touch channel. These electrodes are denoted as X and Y lines. Capacitance measurement is performed sequentially in the order in which touch (X-Y) nodes are specified. 16 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 Mutual capacitance channel (X-Y channels) SAMD20/SAMD21 J (64 pin): up to 16(X) x 16(Y) channels SAMD20/SAMD21 G (48 pin): up to 12(X) x 10(Y) channels SAMD20/SAMD21 E (32 pin): up to 10(X) x 6(Y) channels Figure 2-5. Mutual Capacitance Sensor Arrangement To reduce noise issues due to EMC, use a series resistor with value of 1k on X and Y lines. 2.4.1.2 Self Capacitance Self capacitance method uses a single sense electrode for each touch channel, denoted by a Y line. Capacitance measurement is performed sequentially in the order in which Y lines are specified in the DEF_SELFCAP_LINES configuration parameter. Self capacitance touch button sensor is formed using a single Y line channel, while a touch rotor or slider sensor can be formed using three Y line channels. Self capacitance channel (Y sense lines) SAMD20/SAMD21 J (64 pin): up to 16 channels SAMD20/SAMD21 G (48 pin): up to 10 channels SAMD20/SAMD21 E (32 pin): up to 6 channels Figure 2-6. Self Capacitance - Sensor Arrangement Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 17 Figure 2-7. Self Capacitance - Channel to Sensor Mapping Y sense line can be specified using the configuration parameter DEF_SELFCAP_LINES in non-sequential order. The touch sensors should be enabled in the sequential order of the channels specified using the touch_xxxxcap_sensor_config() API. For improved EMC performance, a series resistor with value of 1 k should be used on X and Y lines. For more information about designing the touch sensor, refer to Buttons, Sliders and Wheels Touch Sensor Design Guide available at www.atmel.com. 2.4.2 Sensor Configuration A mutual capacitance button is formed using a single X-Y channel, while a rotor or slider can be formed using three to eight X-Y channels. A self capacitance button is formed using a single Y channel, while a rotor or slider can be formed using three Y channels. For more information about designing the touch sensor, refer to Buttons, Sliders and Wheels Touch Sensor Design Guide [QTAN0079] ( www.atmel.com). 2.4.3 Acquisition Parameters Filter Level Setting The filter level setting controls the number of samples acquired to resolve each acquisition. A higher filter level setting provides improved signal to noise ratio even under noisy conditions. However, it increases the total time for measuring the signal, which results in increased power consumption. This is applicable for individual channel. Auto Oversample Setting Auto oversample controls the automatic oversampling of sensor channels when unstable signals are detected with the default Filter level setting. Enabling Auto oversample results in Filter level x Auto Oversample number of samples measured on the corresponding sensor channel when an unstable signal is observed. In a case where Filter level is set to FILTER_LEVEL_4 and Auto Oversample is set to AUTO_OS_4, 4 oversamples are collected with stable signal values and 16 oversamples are collected when unstable signal is detected. Auto Oversampling Signal Stability will be determined by the nm_sig_stability_limit variable. A higher Auto oversample setting provides improved signal to noise ratio under noisy conditions, while increasing the total time for measurement resulting in increased power consumption and response time. Auto oversamples can be disabled to obtain best power consumption. Auto oversamples should be configured for individual channel. 18 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 Figure 2-8. Auto Oversamples Auto Tuning Options Auto tuning parameter passed to the calibration API allows users to trade-off between power consumption and noise immunity. Following auto tuning options are available: AUTO_TUNE_NONE - Auto tuning disabled AUTO_TUNE_PRSC - Auto tuning of the PTC prescaler AUTO_TUNE_RSEL - Auto tuning of the series resistor When Auto tuning of the series resistor is selected the PTC is optimized for fastest operation or lowest power operation. The PTC runs at user defined speed and the series resistor is set to the optimum value which still allows full charge transfer. Auto tuning will be performed on individual channel series resistor settings. DEF_XXXXCAP_ SENSE_RESISTOR_PER_NODE will be tuned by the QTouch Safety Library. When Auto tuning of PTC prescaler is selected the performance is optimized for best noise immunity. During calibration, the QTouch Safety Library carries out auto tuning to ensure full charge transfer for each sensor, by adjusting either the internal series resistor or the PTC clock prescaler. The internal series resistor is set to user defined value and the PTC prescaler is adjusted to slow down the PTC operation to ensure full charge transfer. Auto tuning will be performed on individual channel PTC prescaler settings.DEF_XXXXCAP_CLK_PRESCALE_PER_NODE will be tuned by the QTouch Safety Library. Manual tuning can also be performed by passing AUTO_TUNE_NONE as parameter to the calibration function. When manual tuning option is selected, the user defined values of PTC prescaler and series resistor on individual channels are used for PTC operation. Frequency Mode Setting Frequency mode allows users to configure the bursting waveform characteristics for better noise performance in the system. Following frequency modes are available: FREQ_MODE_NONE - Frequency mode is disabled FREQ_MODE_HOP - Frequency mode hopping FREQ_MODE_SPREAD - Frequency mode spread FREQ_MODE_SPREAD_MEDIAN - Frequency mode spread median Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 19 When frequency mode none option is selected, the PTC runs at constant speed selected by the user (in manual tuning mode) or auto tuned frequency (in PTC rescale tune mode). In this case, the median filter is not applied. When frequency mode hopping option is selected, the PTC runs at a frequency hopping cycle selected by the user (in manual tuning mode) or auto tuned frequency cycle (in PTC prescaler tune mode). In this case, the median filter is applied. When frequency mode spread spectrum option is selected, the PTC runs with spread spectrum enabled on frequency selected by the user (in manual tuning mode) or auto tuned frequency (in PTC prescaler tune mode). In this case, the median filter is not applied. When frequency mode spread spectrum median option is selected, the PTC runs with spread spectrum enabled on frequency selected by the user (in manual tuning mode) or auto tuned frequency (in PTC prescaler tune mode). In this case, the median filter is applied. Gain Setting Gain setting is applied for an individual channel to allow a scaling-up of the touch delta upon contact. 2.4.4 Sensor Global Parameters For an overview of the sensor global and sensor specific parameters, refer Section 4.2.2 and Section 4.3 of the QTouch General Library User Guide ( www.atmel.com). Table 2-3. Global Parameters Naming Changes QTouch Safety Library Name DEF_XXXXCAP_TCH_DRIFT_RATE Towards Touch Drift DEF_XXXXCAP_ATCH_DRIFT_RATE Away From Touch Drift DEF_XXXXCAP_ATCH_RECAL_THRESHOLD Away From Touch Recalibration Threshold DEF_XXXXCAP_ATCH_RECAL_DELAY Away From Touch Recalibration delay DEF_XXXXCAP_CAL_SEQ1_COUNT Calibration Sequence Counter 1 DEF_XXXXCAP_CAL_SEQ2_COUNT Calibration Sequence Counter 2 Conventional QTouch Library Name Negative Drift Positive Drift Recalibration Threshold Positive Recalibration Delay Software Calibration Counter 1 Software Calibration Counter 2 Note: Ensure that the value of DEF_XXXXCAP_CAL_SEQ2_COUNT is always less than the value specified in DEF_XXXXCAP_CAL_SEQ1_COUNT. Refer Section 2.4.6 for more information about noise immunity global parameter. 2.4.5 Common Parameters Interrupt Priority Level Setting The Nested Vectored Interrupt Controller (NVIC) in the SAMD20/SAMD21 has four different priority levels. The priority level of the PTC end of conversion ISR can be selected based on application requirements to accommodate time critical operations. To avoid stack overflow, ensure that adequate stack size has been set in the user application. 20 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 2.4.5.1 Measurement Period Setting The measurement period setting is used to configure the periodic interval for touch measurement. 2.4.6 Noise Immunity Global Parameters 2.4.6.1 Noise Measurement Parameters Noise Measurement Enable Disable The DEF_XXXXCAP_NOISE_MEAS_ENABLE parameter is used to enable or disable the noise measurement. 1 - Noise measurement will be enabled. 0 - Noise measurement will be disabled and lockout functionality will not be available. Noise Measurement Signal Stability Limit The parameter DEF_XXXXAP_NOISE_MEAS_SIGNAL_STABILITY_LIMIT defines the stability of the signals for noise measurement. Signal values can change from sample to sample during a window buffer period. The difference between adjacent buffer value is compared to the user configured stability limit. Noise is reported only when two changes occur within the specified window period and only if both of which exceed the stability limit. Range: 1 to 1000 Noise Measurement Limit The DEF_XXXXCAP_NOISE_LIMIT parameter is used to select the noise limit value to trigger sensor lockout functionality. There are two purposes for this parameter: If the noise level calculated during a running window exceeds DEF_XXXXCAP_NOISE_LIMIT, then the corresponding sensors are declared noisy and sensor global noisy bit is set as ‘1’. If the lockout is enabled, and the noise level calculated during a running window exceeds DEF_XXXXCAP_NOISE _LIMIT, then system triggers the sensor lockout functionality. Range: 1 to 255 Noise Measurement Buffer Count The DEF_XXXXCAP_NOISE_MEAS_BUFFER_CNT parameter is used to select the buffer count for noise measurement buffer. Range: 3 to 10 (If N number of samples differences have to be checked, define this parameter as “N + 1”) If N = 4 then set DEF_XXXXCAP_NOISE_MEAS_BUFFER_CNT 5u 2.4.6.2 Sensor LockOut Parameters Sensor Lockout Selection The DEF_XXXXCAP_LOCKOUT_SEL parameter is used to select the lockout functionality method. If DEF_XXXXCAP_LOCKOUT_SEL is set to SINGLE_SENSOR_LOCKOUT and a sensor’s noise level is greater than DEF_XXXXCAP_NOISE_LIMIT, then corresponding sensor is locked out from touch detection and drifting is disabled. If DEF_XXXXCAP_LOCKOUT_SEL is set to GLOBAL_SENSOR_LOCKOUT and any sensor’s noise level is greater than DEF_XXXXCAP_NOISE_LIMIT, then all sensors are locked out from touch detection and drifting is disabled. If DEF_XXXXCAP_LOCKOUT_SEL is set to NO_LOCKOUT, then lockout feature is disabled. Note: Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 21 ̶ Global sensors noisy bit will be available for SINGLE_SENSOR_LOCKOUT and GLOBAL_SENSOR_LOCKOUT. ̶ Global sensors noisy bit will not be available for NO_LOCK_OUT. Range: 0 to 2 Sensor Lockout Countdown If the sensor signal moves from noisy to a good condition and stays there for a DEF_XXXXCAP_LOCKOUT_CNTDOWN number of measurements, the sensor is unlocked and sensors are ready for touch detection and drifting is enabled. Note: This parameter is valid only for global lockout. Range: 1 to 255 2.4.6.3 Frequency Auto Tune Parameters Frequency Auto Tune Enable Disable The DEF_XXXXCAP_FREQ_AUTO_TUNE_ENABLE parameter will enable and disable the frequency auto tune functionality. This feature is applicable only for FREQ_MODE_HOP. 1 - Frequency auto tune will be enabled 0 - Frequency auto tune will be disabled Frequency Auto Tune Signal Stability The DEF_XXXXCAP_FREQ_AUTO_SIGNAL_STABILITY_LIMIT parameter defines the stability limit of signals for deciding the Frequency auto tune. Range: 1 to 1000 Frequency Auto Tune In Counter The DEF_XXXXCAP_FREQ_AUTO_TUNE_IN_CNT parameter is used to trigger the frequency auto tune. If sensor signal change at each frequency exceeds the value specified as DEF_XXXXCAP_FREQ_AUTO_SIGNAL_STABILITY_LIMIT for DEF_XXXXCAP_FREQ_AUTO_TUNE_IN_CNT, then frequency auto tune will be triggered at this frequency. Range: 1 to 255 Note: The Frequency Auto Tune feature and related parameters are available only in FREQ_MODE_HOP mode. 2.4.7 Noise Immunity Features Noise Measurement Noise is measured on a per-channel basis after each channel acquisition, using historical data on a rolling window of successive measurements. Reported noise to exclude the instance of an applied or removed touch contact, but the noise indication must react sufficiently fast that false touch detection before noise lockout is prevented. Signal change from sample to sample during the window buffer is compared to the stability limit. Noise is reported only when two changes occur within the window period and both of which exceed the DEF_XXXXCAP_NOISE_MEAS_SIGNAL_STABILITY_LIMIT limit. Noise is calculated using the following algorithm: if (swing count > 2) { Nk = - ((|Sn – Sn-1| > DEF_XXXXCAP_NOISE_MEAS_SIGNAL_STABILITY))? (0): (|Sn-Sn-1| DEF_XXXXCAP_NOISE_MEAS_SIGNAL_STABILITY)). } else 22 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 { Nk = 0 } The swing count is number of signal changes that exceed DEF_XXXXCAP_NOISE_MEAS_SIGNAL _STABILITY_LIMIT limit during buffer window period. When the measured noise exceeds DEF_XXXXCAP_NOISE_LIMIT, the touch library locks out sensors, reports no touch detection and drifting is stopped. Noise measurement is provided for all the channels. Each byte in p_xxxxcap_measure_data-> p_nm_ch_noise_val provides the noise level associated with that channel. Noise indication is provided for all the sensors configured by the application. A bit is available in p_xxxxcap_measure_data-> p_sensor_noise_status for each sensor to determine whether the sensor is noisy or not. The following code snippet provides the sample code to read the noise status of a particular sensor. If (Double_Inverse_Check is passed on p_xxxxcap_measure_data-> p_sensor_noise_status) { If((GET_XXXXCAP_SENSOR_NOISE_STATUS(SENSOR_NUMBER) == 0 ) { /* Sensor is stable */ } Else { /* Sensor is Unstable */ } else { /* Take fault action on Double inverse check failure */ } Note: Double inverse check must be performed on p_xxxxcap_measure_data-> p_sensor_noise_status variable before using those variables. Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 23 Figure 2-9. Noise Calculation Normal measurement Noise Meas = ENABLE Yes Calculate Noise level Global lockout == Enable No Single key lockout = Enable Yes No Decrement Lockout Countdown No Yes noise value > noise limit && Lockout sensor = noisy Current noise > prev_noise No Decrement the noise value yes Lockout Count =0 Noise value < Noise limit Noise value > Noise limit && ( Yes yes yes Clear lock Bit for all sensor Yes Set Lockout bit for all sensor and Initialize Lockout countdown with MAX value No No No No Set Lockout bit for current sensor and Limit current Noise value = 2 * Noise limit. Sensor Post processing 24 Clear unlock Bit for current sensor Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 2.4.8 Sensor Lockout This feature locks out the sensors when the measured noise exceeds DEF_XXXXCAP_NOISE_LIMIT and does not report a touch. This prevents post-processing. So, the high level of noise cannot cause the channel to drift or recalibrate incorrectly. Safety library presents two types of lockout features: Global sensor lockout When the noise level of a sensor is greater than DEF_XXXXCAP_NOISE_LIMIT, all the sensors are locked out from touch detection and drifting is disabled. Sensor signal changes from noisy to a good condition and stays there for a DEF_XXXXCAP_LOCKOUT_CNTDOWN number of measurements, the sensor is unlocked for touch detection and also available for post processing. Single sensor lockout When the noise level of a sensor is greater than DEF_XXXXCAP_NOISE_LIMIT, corresponding sensor is locked out from touch detection and drifting is disabled. Sensor’s signal moves from noisy to a good condition and the noise value itself becomes the count-down to clear lockout. The count-out time after a noise spike is proportional to the size of the spike. 2.4.9 Frequency Auto Tune The frequency auto tune feature provides the best quality of signal data for touch detection by automatically selecting acquisition frequencies showing the best SNR in FREQ_MODE_HOP mode. During each measurement cycle, the signal change since the last acquisition at the same frequency is recorded for each sensor. After the cycle, when all sensors have been measured at the present acquisition frequency, the largest signal variation of all sensors is stored as the variance for that frequency stage. The variance for each frequency stage is compared to the DEF_XXXXCAP_FREQ_AUTO_TUNE_SIGNAL_STABILITY_LIMIT limit, and if the limit is exceeded, a per-stage counter is incremented. If the measured variance is lower than the limit, the counter is decremented, if it has not been set as zero. If all frequencies display noise exceeding the stability limit, only the counter for the specific frequency stage with the highest variance is incremented after its cycle. When a frequency counter reaches the DEF_XXXXCAP_FREQ_AUTO_TUNE_IN_CNT (auto-tune count in variable), that frequency stage is selected for auto-tuning. A new frequency selection is applied and the counters and variances for all frequencies are reset. After a frequency has been selected for auto-tuning, the count-in for that frequency stage is set to half the original count-in and the process is repeated until either all frequencies have been measured or a frequency is selected which does not re-trigger auto-tuning is determined. If all frequencies have been tested, and the variation exceeds the DEF_XXXXCAP_FREQ_AUTO_TUNE_SIGNAL _STABILITY_LIMIT limit then the frequency with the lowest variance is selected for the frequency stage currently under tuning. The auto-tune process is re-initialized and further tuning does not take place until a frequency stage’s high variance counter again reaches the count in limit. Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 25 Figure 2-10. Frequency Auto-Tune Normal measurement (FREQ_HOP_MODE = ENABLE) && (FREQ_AUTO_TUNE = ENABLE No Yes Signal change of current freq > Stability limit Yes No Decrement Auto tune counter Increment Frequency auto tune in count for this frequency No Auto tune in count > Auto tune_Limit Yes Find the good Frequency and set as current frequency. Noise measurement and System post processing 26 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 2.5 Touch Library Error Reporting Mechanism The application reports the Touch library errors using one of the two mechanisms: Touch Library Error Application Callback mechanism API Return Type mechanism Touch Library Error Application Callback If any touch library error is generated due to failure in the logical program counter flow or internal library checks, the touch library calls the error callback function registered by the application. If error callback is not registered by the application, the touch library will lock the system in an infinite loop. The following sample code block registers the touch library error callback: /* registering the callback */ touch_error_app_cb = touch_lib_error_callback; Note: Before calling any touch library API, register the touch library error callback. For the list of APIs that calls the error call back function, see Section 2.12.2, “Error Codes Returned Through Callback” API Return Type Mechanism Few Touch library APIs can return the error synchronously through function call return. For the list of APIs that return the error synchronously, see Section 2.12.1, “Error Codes Returned Synchronously”. 2.6 Touch Library Program Counter Test The touch library implements two types of tests to verify if the program counter is functioning properly. The logical program tests verifies that the logical sequence of the APIs and processes are appropriate. The program counter test ensures that the program counter is working as expected. 2.6.1 Logical Program Flow Test There are two sub tests. One test ensures that the mandatory sequence of APIs is followed as illustrated in Figure 2-4. The second test tracks various internal processes by maintaining a unique counter for each process. Any error in the logical sequence causes error callback function to be called with error status as TOUCH_LOGICAL_PROGRAM_CNTR_FLOW_ERR. Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 27 Figure 2-11. Example Sequence for Logical Program Flow Error APPLICATION QTOUCH LIBRARY $SSOLFDWLRQDQGWRXFKOLEUDU\LQLWLDOL]DWLRQ 7RXFKOLEUDU\$3,FDOO 12 12 3URJUDPIORZDV H[SHFWHG" <(6 ,VDSSOLFDWLRQHUURU FDOOEDFNUHJLVWHUHG" &RQWLQXHZLWKQRUPDO VHTXHQFH <(6 | Figure 2-12. /RFNWKHV\VWHP $SSOLFDWLRQQHHGV WRKDQGOHHUURU FRQGLWLRQ | Example of a Wrong API Sequence APPLICATION QTOUCH LIBRARY $SSOLFDWLRQ,QLWLDOL]DWLRQ WRXFKB[[[[FDSBVHQVRUVBPHDVXUH 12 12 ,VDSSOLFDWLRQHUURU FDOOEDFNUHJLVWHUHG" <(6 | 28 /RFNWKHV\VWHP $SSOLFDWLRQQHHGV WRKDQGOHHUURU FRQGLWLRQ Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 3URJUDPIORZ DVH[SHFWHG" <(6 &RQWLQXHZLWKQRUPDO VHTXHQFH | 2.6.2 Program Counter Test This is another mechanism using which Program Counter can tested. To test the branching, the following program counter API are provided within the touch library at different flash locations: touch_lib_pc_test_magic_no_1 touch_lib_pc_test_magic_no_2 touch_lib_pc_test_magic_no_3 touch_lib_pc_test_magic_no_4 The application calls these API and check the returned value. Each of these API returns a unique value. Hence it is possible to check if the program counter has jumped to the correct address within the touch library by verifying the unique value it returns. If the expected return value is not returned the application must handle error condition. Note: Ensure that the program counter can branch throughout the touch library. This program counter test is applicable only for checking the program counter validity within the touch library. The following figure illustrates the implementation of the program counter APIs. Figure 2-13. Program Counter Test Using Program Counter APIs APPLICATION QTOUCH LIBRARY Application and Touch library initialization QTouch library API call API return touch_lib_pc_test_magic_no_1 Return TOUCH_PC_FUNC_MAGIC_NO_1 Return Value check passed? NO YES Continue with normal sequence | Application needs to handle error condition | Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 29 2.7 CRC on Touch Input Configuration The data integrity check is performed on the input configuration variables from application to Touch Library. The application calls the touch_calc_xxxxcap_config_data_integrity API, if the input configuration variables has been modified. The touch_test_xxxxcap_config_data_integrity API must be called to test the input configuration data integrity. The periodicity of calling this API can be decided by the application. Note: The touch_calc_xxxxcap_config_data_integrity API must be called after initialization sequence. The following illustration depicts the sequence for verifying the data integrity. 30 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 Figure 2-14. Data Integrity Check Sequence APPLICATION QTOUCH LIBRARY WRXFKB[[[[FDSBVHQVRUVBLQLW WRXFKB[[[[FDSBGLBLQLW WRXFKB[[[[FDSBVHQVRUBFRQILJ WRXFKB[[[[FDSBVHQVRUVBFDOLEUDWH WRXFKBFDOFB[[[[FDSBFRQILJBGDWDBLQWHJULW\ WRXFKB[[[[FDSBVHQVRUVBPHDVXUH WRXFKB[[[[FDSBVHQVRUVBPHDVXUH WRXFKBWHVWB[[[[FDSBFRQILJBGDWDBLQWHJULW\ 12 'DWDLQWHJULW\ WHVWSDVVHG" <(6 $SSOLFDWLRQQHHGV WRKDQGOHHUURU FRQGLWLRQ &RQWLQXHZLWK QRUPDO VHTXHQFH | | WRXFKB[[[[FDSBXSGDWHBJOREDOBSDUDP WRXFKBFDOFB[[[[FDSBFRQILJBGDWDBLQWHJULW\ WRXFKB[[[[FDSBVHQVRUVBPHDVXUH WRXFKB[[[[FDSBVHQVRUVBPHDVXUH WRXFKBWHVWB[[[[FDSBFRQILJBGDWDBLQWHJULW\ 'DWDLQWHJULW\ WHVWSDVVHG" 12 <(6 &RQWLQXHZLWK QRUPDO VHTXHQFH | $SSOLFDWLRQQHHGV WRKDQGOHHUURU FRQGLWLRQ | Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 31 The following APIs modifies the input configuration and hence touch_calc_xxxxcap_config_data_integrity must be called only after calling these APIs. touch_xxxxcap_update_global_param touch_xxxxcap_sensor_update_acq_config touch_xxxxcap_sensor_update_config touch_xxxxcap_cnfg_mois_threshold touch_xxxxcap_cnfg_mois_mltchgrp touch_xxxxcap_mois_tolrnce_enable touch_xxxxcap_mois_tolrnce_disable Notes: 1. touch_calc_xxxxcap_config_data_integrity and touch_test_xxxxcap_config_ data_integrity should be called only when touch library state is TOUCH_STATE_INIT or TOUCH_STATE_READY. 2. If calibration of all channels is requested by application with AUTO_TUNE_PRSC or AUTO_TUNE_RSEL option, QTouch Safety Library will automatically recalculate the CRC at the end of auto tuning calibration process. If there is any fault, library will report error as TOUCH_LIB_CRC_FAIL through errror callback, even before application calls touch_test_xxxxcap_config_data_integrity API. 2.8 Double Inverse Memory Check It is important to check the critical safety data before the application uses such data. Checking each critical data before using it prevents any system malfunction. Double inverse memory check is a mechanism that stores and retrieve data with additional redundancy. Reading and writing redundant data requires some processing and additional memory requirement. Hence, this mechanism is suggested only for the most important safety critical data in the FMEA and QTouch Safety Library. The inverse of all the critical data interface variables used among the application and touch library is stored in the structure variable touch_lib_xxxxcap_param_safety. The mechanism stores the inverse of the critical data in this structure. Before reading and writing the critical data, the authenticity of the critical data is verified. All double inverse variables are part of the touch_lib_param_safety_t structure. These double inverse variables are inverse value of various variables selected from different structure variables. The application must perform the double inverse check whenever it attempts to read or write a critical data interface variables. 2.8.1 Application to Touch Library The application must calculate the inverse for all the variables listed in the column Variable and store it as the corresponding inverse variable listed in the column Inverse Variable. Touch library checks for double inversion between the variables listed in the Inverse Variable column and Variable column. If the verification is successful, touch library operation continues as expected. If the verification is unsuccessful, the touch library calls the error callback function touch_error_app_cb indicating the reason TOUCH_LIB_DI_CHECK_FAIL. The following table provides the list of variables and the corresponding inverse variable for which the application must add double inverse protection. 32 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 Table 2-4. Inverse Variable Details - Application to Touch Library Variable Inverse Variable Description p_channel_signals P_inv_channel_signals Refer Section 3.4.5 for variable and Section 3.4.2 for corresponding inverse variable. current_time_ms inv_current_time_ms Refer Section 3.4.7 for variable and Section 3.4.2 for corresponding inverse variable. burst_again inv_burst_again Refer Section 2.9 for variable and Section 3.4.2 for corresponding inverse variable. acq_mode inv_acq_mode Refer Section 3.3.8 for variable and Section 3.4.2 for corresponding inverse variable. Figure 2-15. Example Sequence for Processing Double Inverse Variable (Application to QTouch Safety Library) APPLICATION QTOUCH LIBRARY Application and Touch library initialization Application computes the inverse of safety critical data and stores them API call or return from filter callback function Touch library performs a double inverse check on the safety critical data NO NO Is Application error callback registered? YES Lock the system | 2.8.2 Double inverse check passed YES Continue with the normal sequence Application needs to handle error condition | Touch Library to Application The touch library must calculate the inverse for all the variables listed in the column Variable and store it as the corresponding inverse variable listed in the column Inverse Variable. Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 33 Application must check for double inversion between the variables listed in the Inverse Variable column and Variable column. Appropriate action must be performed by the application if double inversion check fails. 34 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 The following table lists the variables and the corresponding inverse variable for which the touch library will add double inverse protection. Table 2-5. Inverse Variable Details Touch Library to Application Variable Inverse Variable Description p_channel_signals p_inv_channel_signals Refer Section 3.4.5 for variable and Section 3.4.2 for corresponding inverse variable. acq_status inv_acq_status Refer Section 3.4.5 for variable and Section 3.4.2 for corresponding inverse variable. num_channel_signals inv_num_channel_signals Refer Section 3.4.5 for variable and Section 3.4.2 for corresponding inverse variable. num_sensor_states p_inv_sensor_states Refer Section 3.4.5 for variable and Section 3.4.2 for corresponding inverse variable. p_sensor_states inv_num_sensor_states Refer Section 3.4.5 for variable and Section 3.4.2 for corresponding inverse variable. num_rotor_slider_values inv_num_rotor_slider_values Refer Section 3.4.5 for variable and Section 3.4.2 for corresponding inverse variable. p_rotor_slider_values p_inv_rotor_slider_values Refer Section 3.4.5 for variable and Section 3.4.2 for corresponding inverse variable. lib_state inv_lib_state Refer Section 3.4.8 for variable and Section 3.4.2 for corresponding inverse variable. delta inv_delta Refer Section 3.4.8 for variable and Section 3.4.2 for corresponding inverse variable. sf_ptc_error_flag inv_sf_ptc_error_flag This variable is used by FMEA and should not be used by the application. cc_cal_open_calibration _vals inv_cc_cal_open_calibration _vals This variable is used by FMEA and should not be used by the application. p_sensor_noise_status p_inv_sensor_noise status p_inv_sensor_mois_status p_sensor_mois_status p_auto_os_status p_inv_chan_auto_os_status Refer Section 3.4.5 for variable and Section 3.4.2 for corresponding inverse variable. Refer Section 3.4.5 for variable and Section 3.4.2 for corresponding inverse variable. Refer Section 3.4.5 for variable and Section 3.4.2 for corresponding inverse variable. Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 35 Note: p_channel_signals variable must be double inversed by both the application and the touch library. The application can apply filtering mechanism on the channel signals in the filter callback function. The application must check for the double inversion before modifying the channel signals. After modifying the channel signals, the application would store the value of the channel signals into the p_inv_channel_signals variable. The Touch Library after returning from the filter callback function, would re-check for double inversion on the channel signals. Figure 2-16. Example Sequence for ProcessinggDouble Inverse Variable ( APPLICATION y ) QTOUCH LIBRARY Application and Touch library initialization Qtouch library api call Library computes inverse of safety critical data and stores them API return or filter callback Application performs double inverse check on safety critical data Double inverse check passed? NO YES Continue with normal sequence Application needs to handle error condition | 2.9 | Application Burst Again Mechanism The completion of a touch measurement is indicated by the touch library by calling the function touch_xxxxcap_measure_complete_callback().The complete callback function will be called on completion of the previously initiated touch measurement. The application can call the touch measurement again based on touch measurement periodicity or initiate the next measurement immediately by returning a value 1 in the touch_xxxxcap_measure_complete_callback() function. The touch library will initiate the next measurement immediately if application returns a value 1 when the complete callback function is called and the internal burst again flag is set by the library. If the application returns 0, the touch library waits for another touch measurement to be initiated by the application by calling touch_xxxxcap_sensors_measure() to perform another touch measurement. Refer Figure 2-4 for more information. 2.10 Memory Requirement The table provided in this section provides the typical code and data memory required for QTouch Safety Library. 36 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 Mutual and self capacitance measurement method requires additional data memory for the application to store the signals, references, sensor configuration information, and touch status. This data memory is provided by the application as data block array. The size of this data block depends on the number of Channels, sensors and rotor sliders configured. Default Configuration Used For Memory Requirement Calculations: Apart from the various combinations mentioned in Section 2.10.1. The default configuration details used in all the cases applicable for memory calculation in Section 2.10.1 are mentioned in the following table. Table 2-6. Default Configuration CONFIGURATION MUTLCAP SELFCAP DEF_XXXXCAP_NOISE_MEAS_ENABLE 1 1 DEF_XXXXCAP_FREQ_AUTO_TUNE_ENABLE 1 1 DEF_XXXCAP_NOISE_MEAS_BUFFER_CNT 5 5 DEF_XXXCAP_MOIS_TOLERANCE_ENABLE 1 1 DEF_XXXCAP_NUM_MOIS_GROUPS 8 8 2.10.1 Table 2-7. Memory Requirement for IAR Safety library Memory Requirement for Mutual Capacitance Total No of Channels No of Keys No of rotor/slider Total Code Memory Total Data Memory 1 1 0 23275 1720 10 10 0 23296 2180 10 2 2 24925 2172 20 20 0 23286 2664 20 10 2 24913 2640 40 40 0 23255 3664 256 20 5 24884 3620 256 256 0 23185 14568 256 200 14 24812 14400 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 37 Table 2-8. Memory Requirement Self Capacitance Total No of Channels No of Keys No of rotor/slider Total Code Memory Total Data Memory 1 1 0 22884 1700 2 2 0 22887 1744 11 11 0 22880 2188 11 2 3 24412 2232 16 16 0 22868 2412 16 4 4 24398 2468 Table 2-9. Memory Requirement (Self + Mutual) Capacitance Total No of Mutual Cap Channels Total No of SelfCap Channels Total No of Mutual Cap Keys Total No of Self Cap Keys Total No of Mutual Cap Rotor Sliders Total No of Self Cap Rotor Sliders Total Code Memory Total Data Memory 1 1 1 1 0 0 28556 2080 40 8 40 8 0 0 28510 4356 40 8 40 2 0 2 30042 4392 40 8 24 8 3 0 30138 4300 40 8 8 2 3 2 31669 4336 80 11 80 11 0 0 28522 6548 80 11 80 2 0 3 30054 6592 80 11 48 11 6 0 30148 6412 80 11 48 2 6 3 31680 6456 2.11 API Execution Time 2.11.1 Mutual Capacitance API Execution Time This section provides the time required for various mutual capacitance APIs. The values provided are based on the following system configuration: CPU Frequency: 48MHz PTC Frequency: 4MHz No of Channels: 20 No of Sensors: 10 38 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 No of Keys: 8 No of Rotor/sliders: 2 Table 2-10. Default Configuration - Mutual Capacitance CONFIGURATION MUTLCAP DEF_XXXXCAP_NOISE_MEAS_ENABLE 1 DEF_XXXXCAP_FREQ_AUTO_TUNE_ENABLE 1 DEF_XXXCAP_NOISE_MEAS_BUFFER_CNT 5 DEF_XXXCAP_MOIS_TOLERANCE_ENABLE 1 DEF_XXXCAP_NUM_MOIS_GROUPS 8 Table 2-11. Execution Time for Various QTouch Safety Library APIs - Mutual Capacitance API Time Units touch_mutlcap_sensors_init 412.7 µs touch_mutlcap_di_init 14.04 µs touch_mutlcap_sensor_config 19.83 µs touch_mutlcap_sensors_calibrate 210.6* ms touch_mutlcap_calibrate_single_sensor 24.84* ms touch_mutlcap_sensors_measure 17.1* ms touch_calc_mutlcap_config_data_integrity 1250 µs touch_test_mutlcap_config_data_integrity 1250 µs touch_mutlcap_sensor_get_delta 10.79 µs touch_mutlcap_sensor_update_config 8.48 µs touch_mutlcap_sensor_get_config 6.59 µs touch_mutlcap_sensor_update_acq_config 60.05 µs touch_mutlcap_sensor_get_acq_config 34.55 µs touch_mutlcap_update_global_param 8.04 µs touch_mutlcap_get_global_param 6.25 µs touch_mutlcap_get_libinfo 6.5 µs touch_lib_pc_test_magic_no_1 3.67 µs touch_lib_pc_test_magic_no_2 3.39 µs touch_lib_pc_test_magic_no_3 3.39 µs touch_lib_pc_test_magic_no_4 3.39 µs touch_mutlcap_cnfg_mois_mltchgrp 6.06 µs touch_mutlcap_cnfg_mois_threshold 6.19 µs Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 39 Table 2-11. Execution Time for Various QTouch Safety Library APIs - Mutual Capacitance API Time Units touch_mutlcap_mois_tolrnce_enable 4.56 µs touch_mutlcap_mois_tolrnce_disable 7.72 µs touch_mutlcap_sensor_reenable 24.17 µs touch_mutlcap_sensor_disable 14.67 µs touch_library_get_version_info 4.35 µs touch_suspend_ptc 2.0 ms touch_resume_ptc 8.0 µs touch_disable_ptc 5.0 µs touch_enable_ptc 5.0 µs 183.8 µs touch_mutlcap_sensors_deinit Notes: 1. The Table 2-11 provides the maximum time required for the touch_mutlcap_sensors_calibrate, touch_mutlcap_calibrate_single_sensor, touch_mutlcap_sensors_measure,and touch_suspend_ptc API to complete the procedure. The time required for the API to return control to the application will be much shorter than the time specified in the Table 2-11. After the control is returned back to the application, the application can execute other non-touch related tasks. 2. API Execution time marked as * are calculated for sensors mentioned in Section 2.11.1 with typical sensor capacitance values. Table 2-12. Timings for APIs to Return Control to the Application API Time Units touch_mutlcap_sensors_calibrate 151.9 µs touch_mutlcap_calibrate_single_sensor 17.79 µs touch_mutlcap_sensors_measure 85.7 µs touch_suspend_ptc 4.2 µs 2.11.2 Self Capacitance API Execution Time This section provides the time required for various self capacitance APIs. The values provided are based on the following system configuration: CPU Frequency: 48MHz PTC Frequency: 4MHz No of Channels: 16 No of Sensors: 8 No of Keys: 4 No of Rotor/sliders: 4 40 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 Table 2-13. Default Configuration - Self Capacitance CONFIGURATION SELFCAP DEF_XXXXCAP_NOISE_MEAS_ENABLE 1 DEF_XXXXCAP_FREQ_AUTO_TUNE_ENABLE 1 DEF_XXXCAP_NOISE_MEAS_BUFFER_CNT 5 DEF_XXXCAP_MOIS_TOLERANCE_ENABLE 1 DEF_XXXCAP_NUM_MOIS_GROUPS 8 Table 2-14. Execution Time for Various QTouch Safety Library APIs - Self Capacitance API Time Units 313.7 µs 12 µs touch_selfcap_sensor_config 18.35 µs touch_selfcap_sensors_calibrate 566.7* ms touch_selfcap_calibrate_single_sensor 73.89* ms touch_selfcap_sensors_measure 47.95* ms touch_calc_selfcap_config_data_integrity 1041 µs touch_test_selfcap_config_data_integrity 1040 µs touch_selfcap_sensor_get_delta 10.54 µs touch_selfcap_sensor_update_config 7.47 µs touch_selfcap_sensor_get_config 6.1 µs touch_selfcap_sensor_update_acq_config 19.62 µs touch_selfcap_sensor_get_acq_config 29.54 µs touch_selfcap_update_global_param 8.18 µs touch_selfcap_get_global_param 5.97 µs touch_selfcap_get_libinfo 6.39 µs touch_lib_pc_test_magic_no_1 3.67 µs touch_lib_pc_test_magic_no_2 3.53 µs touch_lib_pc_test_magic_no_3 3.39 µs touch_lib_pc_test_magic_no_4 3.39 µs touch_selfcap_cnfg_mois_mltchgrp 5.59 µs touch_selfcap_cnfg_mois_threshold 6.1 µs touch_selfcap_mois_tolrnce_enable 4.74 µs touch_selfcap_mois_tolrnce_disable 7.28 µs touch_selfcap_sensors_init touch_selfcap_di_init Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 41 Table 2-14. Execution Time for Various QTouch Safety Library APIs - Self Capacitance API Time Units touch_selfcap_sensor_reenable 24.17 µs touch_selfcap_sensor_disable 14.63 µs 4.2 µs 155.8 µs touch_library_get_version_info touch_selfcap_sensors_deinit Notes: 1. The Table 2-14 provides the maximum time required for the touch_selfcap_sensors_calibrate, touch_selfcap_calibrate_single_sensor, and touch_selfcap_sensors_measure API to complete the procedure. The time required for the API to return control to the application will be much shorter than the time specified in the Table 2-14. After the control is returned back to the application, the application can execute other non-touch related tasks. 2. API Execution Time marked as * are calculated for sensors mentioned in Section 2.11.2, “Self Capacitance API Execution Time” with typical sensor capacitance values. 42 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 Table 2-15. Timings for APIs to Return Control to the Application API Time Units touch_selfcap_sensors_calibrate 138.2 µs touch_selfcap_calibrate_single_sensor 13.73 µs touch_selfcap_sensors_measure 139.9 µs 2.12 Error Interpretation This section provides information about the error bits that indicate the errors and the specific reason that causes the errors. 2.12.1 Error Codes Returned Synchronously The following table provides the error codes returned by various touch APIs synchronously through function call return. Table 2-16. Error Codes Returned Synchronously API Error Bit Reason TOUCH_INVALID_INPUT_PARAM Input parameters are invalid. TOUCH_INVALID_MUTLCAP_CONF IG_PARAM Configuration parameters are invalid. TOUCH_INVALID_LIB_STATE Library state is invalid. TOUCH_INVALID_RECAL_THRESH OLD Recalibration threshold is invalid. TOUCH_INVALID_INPUT_PARAM Input parameters are invalid. TOUCH_INVALID_INPUT_PARAM Input parameters are invalid. TOUCH_INVALID_LIB_STATE Library state is invalid. TOUCH_INVALID_SENSOR_TYPE Sensor type is invalid. TOUCH_INVALID_CHANNEL_NUM Channel number is invalid. TOUCH_INVALID_RS_NUM Invalid rotor slider number. TOUCH_INVALID_LIB_STATE Library state is invalid. TOUCH_CNFG_MISMATCH Configuration mismatch error. TOUCH_INVALID_LIB_STATE Library state is invalid. TOUCH_INVALID_SENSOR_ID Sensor ID is invalid. TOUCH_ACQ_INCOMPLETE Acquisition is in progress. TOUCH_INVALID_LIB_STATE Library state is invalid. TOUCH_ALL_SENSORS_DISABLED All sensors are disabled. TOUCH_INVALID_INPUT_PARAM Input parameters are invalid. touch_xxxxcap_sensors_init touch_xxxxcap_di_init touch_xxxxcap_sensor_config touch_xxxxcap_sensors_calibrate touch_xxxxcap_calibrate_single_ sensor touch_xxxxcap_sensors_measure touch_xxxxcap_sensor_get_delta Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 43 Table 2-16. Error Codes Returned Synchronously API Error Bit Reason touch_xxxxcap_sensor_update_con fig TOUCH_INVALID_INPUT_PARAM Input parameters are invalid. TOUCH_INVALID_LIB_STATE Library state is invalid. TOUCH_INVALID_INPUT_PARAM Input parameters are invalid. TOUCH_INVALID_LIB_STATE Library state is invalid. TOUCH_INVALID_SENSOR_ID Sensor ID is invalid. TOUCH_INVALID_INPUT_PARAM Input parameters are invalid. TOUCH_INVALID_RECAL_THRESH OLD Recalibration threshold is invalid. TOUCH_INVALID_LIB_STATE Library state is invalid. TOUCH_INVALID_INPUT_PARAM Input parameters are invalid. TOUCH_INVALID_LIB_STATE Library state is invalid. touch_xxxxcap_sensor_update_acq _config TOUCH_INVALID_INPUT_PARAM Input parameters are invalid. TOUCH_INVALID_LIB_STATE Library state is invalid. touch_xxxxcap_sensor_get_acq_co nfig TOUCH_INVALID_INPUT_PARAM Input parameters are invalid. TOUCH_INVALID_LIB_STATE Library state is invalid. touch_xxxxcap_get_libinfo TOUCH_INVALID_INPUT_PARAM Input parameters are invalid. TOUCH_INVALID_INPUT_PARAM Input parameters are invalid. TOUCH_INVALID_LIB_STATE Library state is invalid. TOUCH_INVALID_INPUT_PARAM Input parameters are invalid. TOUCH_INVALID_LIB_STATE Library state is invalid. touch_xxxxcap_cnfg_mois_mltchgr p TOUCH_INVALID_INPUT_PARAM Input parameters are invalid. touch_xxxxcap_cnfg_mois_thresho ld TOUCH_INVALID_INPUT_PARAM Input parameters are invalid. touch_xxxxcap_mois_tolrnce_enab le TOUCH_INVALID_INPUT_PARAM Input parameters are invalid. TOUCH_CNFG_MISMATCH Configuration mismatch error TOUCH_INVALID_INPUT_PARAM Input parameters are invalid. TOUCH_CNFG_MISMATCH Configuration mismatch error touch_library_get_version_info TOUCH_INVALID_INPUT_PARAM Input parameters are invalid touch_suspend_ptc TOUCH_INVALID_INPUT_PARAM Suspend application callback is not registered TOUCH_INVALID_LIB_STATE PTC is already suspended TOUCH_INVALID_LIB_STATE PTC is already resumed touch_xxxxcap_sensor_get_config touch_xxxxcap_update_global_par am touch_xxxxcap_get_global_param touch_xxxxcap_sensor_reenable touch_xxxxcap_sensor_disable touch_xxxxcap_mois_tolrnce_disa ble touch_resume_ptc 44 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 Table 2-16. Error Codes Returned Synchronously API touch_calc_xxxxcap_config_data_ integrity touch_test_xxxxcap_config_data_ integrity Error Bit Reason TOUCH_INVALID_LIB_STATE Library state is invalid.Should be called when library state is TOUCH_STATE_INIT or TOUCH_STATE_READY. TOUCH_INVALID_LIB_STATE Library state is invalid.Should be called when library state is TOUCH_STATE_INIT or TOUCH_STATE_READY. TOUCH_INVALID_LIB_STATE touch_xxxxcap_sensors_deinit Library state is invalid.Should be called when library state is TOUCH_STATE_INIT or TOUCH_STATE_READY. 2.12.2 Error Codes Returned Through Callback The following table provides the list of APIs and the associated error codes that results in touch_library_error_callback being called. Table 2-17. API Error Codes Returned through Callback API Error Bit Reason touch_xxxxcap_sensor_init TOUCH_LOGICAL_PROGRAM_CNTR _FLOW_ERR Logical program counter flow error. TOUCH_PINS_VALIDATION_FAIL Touch library Pins Invalid. touch_xxxxcap_sensor_config TOUCH_LOGICAL_PROGRAM_CNTR _FLOW_ERR Logical program counter flow error. touch_xxxxcap_di_init TOUCH_LOGICAL_PROGRAM_CNTR _FLOW_ERR Logical program counter flow error. touch_xxxxcap_sensors_calibrate TOUCH_LOGICAL_PROGRAM_CNTR _FLOW_ERR Logical program counter flow error. touch_xxxxcap_calibrate_single_s ensor TOUCH_LOGICAL_PROGRAM_CNTR _FLOW_ERR Logical program counter flow error. TOUCH_LOGICAL_PROGRAM_CNT_ FAIL Logical program counter flow error. TOUCH_LIB_DI_CHECK_FAIL Double inverse check failed. TOUCH_LIB_CRC_FAIL CRC failure during Calibration process. TOUCH_LIB_CRC_FAIL CRC check failed. touch_xxxxcap_sensors_measure touch_test_xxxxcap_config_data_i ntegrity Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 45 2.13 Data and Function Protection The functions and global variables that are used only by Touch Library are marked as static. The user / application must not change these variable to non-static. The header file touch_fmea_api_samd.h file is used only by FMEA. Hence, the application should not include the same in any file. Table 2-18. API Header File Details Header File Availability for Application touch_safety_api_samd.h Yes touch_fmea_api_samd.h Yes 2.14 Moisture Tolerance Moisture tolerance check executes at the end of each measurement cycle and compares the sum of delta of all sensors in a moisture tolerance group against pre-configured threshold. If delta sum is greater than sensor moisture lock threshold and less than system moisture lock threshold, then the ON-state sensors within moisture tolerance group will be considered as moisture affected. If delta sum is greater than system moisture lock threshold, all sensors within the moisture tolerance group will be considered as moisture affected. This condition is referred as moisture global lock out. The safety library will come out of the moisture global lock out state when delta sum is less than threshold for 5 consecutive measurements. Self cap and mutual cap sensors cannot be configured in a single moisture group, Self cap moisture tolerance and mutual cap Moisture tolerance features can be enabled or disabled separately. 2.14.1 Moisture Tolerance Group This feature enables the customer application to group a set of sensors in to single moisture tolerance group. If moisture on one sensor might affect other sensors due to physical proximity, they must be grouped together into one Moisture tolerance group. Using this feature the application can disable moisture tolerance detection for a set of sensors, Multiple Moisture tolerance groups can be formed by the customer application. The library supports up to a maximum of 8 moisture groups. Note: Changing the moisture tolerance group configuration during runtime is not recommended. However, muti-touch group configuration can be changed during runtime. 2.14.2 Multi-touch Group If the user wants to touch multiple sensors within the moisture tolerance group simultaneously to indicate a specific request, then the application should configure those sensors into single multi-touch group. Multiple multi-touch groups can be formed by the customer application. The library supports a maximum of 8 multi-touch groups within a single moisture tolerance group. Moisture tolerance feature improves a system’s performance under the following scenarios: Droplets of water sprayed on the front panel surface Heavy water poured on the front panel surface Large water puddle on multiple sensors Trickling water on multiple sensors 46 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 Moisture tolerance feature is not expected to offer any significant performance improvement under the following scenarios: Large isolated puddle on single sensor Direct water pour on single sensor Within the same moisture group, user should not configure all the sensors to the single multi-touch group. Figure 2-17. Moisture Tolerance Algorithm START Start Process for first moisture group Calculate delta sum of all Sensors configured in the moisture group No any sensor is in detect ? Yes Any multi touch group in detect ? No Yes Calculate multi touch group delta and Subtract from delta sum No Find the first sensor in the group in ON state and subtract it’s delta from delta sum Is delta sum > Sensor moisture lock Threshold Yes No No Is Moisture global Lock out is set? Yes Yes Global Moisture lock out All sensors moisture status bits are set to one Decrement lock count Is Lock count Zero ? Is delta sum < System moisture lock Threshold Set moisture detect status of the sensors that are in detect No Yes Reset All sensors moisture status bits No Is this the Last moisture group ? Set Next Moisture group Yes END 2.15 Quick Re-burst This feature allows faster resolution of a sensor’s state during DI filtering. If Sensor-N is touched by the user, then any other sensor that meets one of the following criteria is selected for the measurement in the next cycle: Same AKS group as Sensor-N Same Moisture tolerance group Sensor-N If quick re-burst feature is disabled, then all sensors would be measured in every measurement cycle. Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 47 2.15.1 Synchronizing Quick Re-burst and Application Burst again Table 2-19. Quick Re-burst - Triggers and Sensors Quick Re-burst Status Measurement Trigger List of Sensors Measured Enabled touch_xxxxcap_sen sors_measure() All Enabled Application Burst Again Sensors that are touched and their AKS and moisture tolerance group sensors Disabled touch_xxxxcap_sen sors_measure() All Disabled Application burst again All 2.16 Reading Sensor States When noise immunity and moisture tolerance features are enabled the validity of the sensor sate is based on the moisture status and noise status. Refer to Section 2.4.7 and Section 2.14 for information on noise immunity and moisture tolerance status of sensors. The state of a sensor is valid only when the sensor is not affected by noise and moisture. If a sensor is noisy or affected by moisture, then the state of sensor must be considered as OFF. The code snippet below depicts the same for mutual-cap sensors. When a sensor is touched or released during DI, library will burst on channels corresponding to sensors whose state is other than OFF or DISABLED. If any sensor in an AKS group is in a state other than OFF or DISABLED, the library will burst channels corresponding sensors belong to that AKS group. If a sensor in any moisture group is in a state other than OFF or DISABLED, the library will burst on channels corresponding to sensors belonging to that moisture group. If(! (GET_MUTLCAP_SENSOR_NOISE_STATUS(SENSOR_NUMBER))) { If(! (GET_MUTLCAP_SENSOR_MOIS_STATUS (SENSOR_NUMBER))) { /*Sensor state is valid Read sensor state */ } else { /* Sensor is Moisture affected*/ } }else { /* Sensor is noisy */ } 2.17 Touch Library Suspend Resume Operation The touch library provides touch_suspend_ptc,touch_resume_ptc API to suspend and resume the PTC. When suspend API is called, the touch library initiates the suspend operation and return to the application.After completing the current PTC conversion, the touch library will initiate suspend operation and call the application touch suspend callback function pointer. The suspend complete callback function pointer has to be registered by the application (Refer Section 3.5.3 for more details). 48 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 Note: The application then should disable the corresponding PTC clock to reduce the power consumption.APP_TOUCH_BUSY and APP_FMEA_OPEN_IN_PROGRESS needs to be maintained by the application. The APP_TOUCH_BUSY will be set to 1 until the completion of following APIs as mentioned in Table 215. The APP_FMEA_OPEN_IN_PROGRESS will be set to 1 until the completion of API mentioned in Table 4-4. The following flowchart depicts the suspend sequence. Figure 2-18. Suspension Sequence SUPENSION_START Disable Interrupts Touch_suspend_ptc() APP_TOUCH_BUSY==1 or APP_FMEA_OPEN_IN_PROGRESS==1 Yes Enable Interrupts No Is Callback Received? No Wait for touch_suspend_callback or perform some other application code without calling any Touch_lib APIs or FMEA APIs Yes Enable Interrupts disable PTC GCLK disable APBCMASK disable GCLK generator disable GCLK source SUSPENSION_COMPLETE Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 49 The following flowchart depicts the resume sequence. Figure 2-19. Resumption Sequence RESUMPTION_START re-enable GLCK source re-enable GCLK generator re-enable APBCMASK reenable the PTC GCLK Touch_resume_ptc() RESUMPTION_COMPLETE Note: The suspend and resume operation must be followed as specified in Section 2.17, otherwise the touch library may not behave as expected. Once the suspend API is called, the touch library resumption should happen before calling any other API's. 2.18 Drifting on Disabled Sensors Touch Safety library performs drifting on disabled sensors. Drifting for disabled sensors would function in a same way, as drifting happens on a sensor which is in 'OFF' state. Hence, drift configuration settings which are applicable for 'OFF' state sensors would be applicable for disabled sensors also. When a sensor is touched, it goes to 'ON' state and if it is disabled in this condition, drifting will adjust the reference to unintentional signal value. Hence for drifting on disabled sensor to function properly, following conditions has to be ensured before that sensor is disabled. ̶ The state of that particular sensor should be 'OFF'. ̶ TOUCH_BURST_AGAIN' bit field in 'p_xxxxcap_measure_data->acq_status' should be '0'. Refer Section 3.6.13, “Touch Library Enable Disable Sensor”. Note: a. It is recomended to re-enable the sensors periodically so that drifting could be done with respect to latest signal values and reference would be adjusted with respect to latest signal values. In other case, if sensors are re-enabled after a long duration, they can be re-enabled with calibration option(no_calib = 0). b. Drifting on Disabled sensors functionality would be applicable if sensors are re-enabled without calibration.If sensors are re-enabled with calibration, then reference would be adjusted as part of calibration process itself. 50 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 3. QTouch Safety Library API 3.1 Typedefs Keyword Type Description threshold_t uint8_t An unsigned 8-bit number setting a sensor detection threshold. sensor_id_t uint8_t Sensor number type. touch_current_time_t uint16_t Current time type. touch_delta_t int16_t Touch sensor delta value type. touch_acq_status_t uint16_t Status of touch measurement. 3.2 Macros 3.2.1 Touch Library Acquisition Status Bit Fields. Keyword Type Description TOUCH_NO_ACTIVITY 0x0000u No touch activity TOUCH_IN_DETECT 0x0001u At least one touch channel is in detect. TOUCH_STATUS_CHANGE 0x0002u Change in touch status of at least one Touch channel. TOUCH_ROTOR_SLIDER_POS_CHANGE 0x0004u Change in the position of at least one rotor or slider. TOUCH_CHANNEL_REF_CHANGE 0x0008u Change in the reference value of at least one touch channel. TOUCH_BURST_AGAIN 0x0100u Indicates that re-burst is required to resolve filtering or calibration state. TOUCH_RESOLVE_CAL 0x0200u Indicates that re-burst is required to resolve calibration process. TOUCH_RESOLVE_FILTERIN 0x0400u Indicates that re-burst is required to resolve calibration. TOUCH_RESOLVE_DI 0x0800u Indicates that re-burst is needed to resolve Detect Integration. TOUCH_RESOLVE_POS_RECAL 0x1000u Indicates that re-burst is needed to resolve away from touch recalibration. TOUCH_CC_CALIB_ERROR 0x2000u Indicates that CC Calibration error has occurred. TOUCH_AUTO_OS_IN_PROGRESS 0x4000u Indicates that Auto Oversample process is going on. DEF_TOUCH_MUTLCAP must be set to 1 in the application to enable the Mutual Capacitance touch technology. DEF_TOUCH_SELFCAP must be set to 1 in the application to enable the Self Capacitance touch technology. Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 51 TOUCH_SAFETY_COMPILE_CHECK must be set to 1 to enable the compile time check feature. 3.2.2 Sensor State Configurations. GET_SENSOR_STATE (SENSOR_NUMBER) To get the sensor state (whether detect or not). These values are valid for parameter that corresponds to the sensor specified using the SENSOR_NUMBER. The macro returns either 0 or 1. If the bit value is 0, the sensor is not in detect. If the bit value is 1, the sensor is in detect. #define GET_XXXXCAP_SENSOR_STATE(SENSOR_NUMBER) p_xxxxcap_measure_data-> p_sensor_states [(SENSOR_NUMBER / 8)] & (1 << (SENSOR_NUMBER % 8))) >> (SENSOR_NUMBER % 8) GET_ROTOR_SLIDER_POSITION (ROTOR_SLIDER_NUMBER) To get the rotor angle or slider position. These values are valid only when the sensor state for corresponding rotor or slider state is in detect. ROTOR_SLIDER_NUMBER is the parameter for which the position is being obtained. The macro returns rotor angle or sensor position. #define GET_XXXXCAP_ROTOR_SLIDER_POSITION(ROTOR_SLIDER_NUMBER) p_xxxxcap_measure_data->p_rotor_slider_values [ROTOR_SLIDER_NUMBER] GET_XXXXCAP_SENSOR_NOISE_STATUS (SENSOR_NUMBER) To get the noise status of a particular sensor. The return value is 1 in case of sensor is noisy and returns 0 if sensor is not noisy. #define GET_XXXXCAP_SENSOR_NOISE_STATUS (SENSOR_NUMBER) (p_xxxxcap_measure_data->p_sensor_noise_status [(SENSOR_NUMBER / 8)] & (1 << (SENSOR_NUMBER % 8))) >> (SENSOR_NUMBER % 8) GET_XXXXCAP_SENSOR_MOIS_STATUS (SENSOR_NUMBER) To get the moisture status of a particular sensor. The return value is 1 in case of sensor is moisture affected and returns 0 if sensor is not moisture affected. #define GET_XXXXCAP_SENSOR_MOIS_STATUS (SENSOR_NUMBER) (p_xxxxcap_measure_data-> \p_sensor_mois_status [(SENSOR_NUMBER / 8)] & (1 << (SENSOR_NUMBER % 8))) >> (SENSOR_NUMBER % 8)) GET_XXXXCAP_AUTO_OS_CHAN_STATUS(CHAN_NUM) To get the auto oversample status of a particular channel. The return value is 1 in case of channel auto oversample is going on and returns 0 if channel auto oversample process is not going on. #define GET_XXXXCAP_AUTO_OS_CHAN_STATUS (CHAN_NUM) (p_xxxxcap_measure_data->p_auto_os_status [(CHAN_NUM / 8)] & (1 << (CHAN_NUM % 8))) >> (CHAN_NUM % 8)) 52 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 3.3 Enumerations 3.3.1 Touch Library GAIN Setting(tag_gain_t) Detailed Description Gain per touch channel. Gain is applied for an individual channel to allow a scaling-up of the touch delta. Delta on touch contact is measured on each sensor. The resting signal is ignored. Range: GAIN_1 (no scaling) to GAIN_32 (scale-up by 32). Data Fields GAIN_1 GAIN_2 GAIN_4 GAIN_8 GAIN_16 GAIN_32 3.3.2 Filter Level Setting (tag_filter_level_t) Detailed Description Touch library FILTER LEVEL setting. The filter level setting controls the number of samples acquired to resolve each acquisition. A higher filter level setting provides improved signal to noise ratio under noisy conditions, while increasing the total time for measurement which results in increased power consumption. The filter level should be configured for each channel. Refer filter_level_t in touch_safety_api_samd.h Range: FILTER_LEVEL_1 (one sample) to FILTER_LEVEL_64 (64 samples). Data Fields FILTER_LEVEL_1 FILTER_LEVEL_2 FILTER_LEVEL_4 FILTER_LEVEL_8 FILTER_LEVEL_16 FILTER_LEVEL_32 FILTER_LEVEL_64 3.3.3 Touch Library AUTO OS Setting (tag_auto_os_t) Detailed Description Auto oversample controls the automatic oversampling of sensor channels when unstable signals are detected with the default setting of filter level. Each increment of Auto Oversample doubles the number of samples acquired from the corresponding sensor channel when an unstable signal is observed. The auto oversample should be configured for each channel. For example, when filter level is set to FILTER_LEVEL_4 and Auto Oversample is set to AUTO_OS_4, 4 oversamples are collected with stable signal values and 16 oversamples are collected when unstable signal is detected. Refer auto_os_t in touch_safety_api_samd.h Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 53 Range: AUTO_OS_DISABLE (oversample disabled) to AUTO_OS_128 (128 oversamples). Data Fields AUTO_OS_DISABLE AUTO_OS_2 AUTO_OS_4 AUTO_OS_8 AUTO_OS_16 AUTO_OS_32 AUTO_OS_64 AUTO_OS_128 3.3.4 Library Error Code (tag_touch_ret_t) Detailed Description Touch Library error codes. Data Fields TOUCH_SUCCESS Successful completion of touch operation. TOUCH_ACQ_INCOMPLETE Library is busy with pending previous touch measurement. TOUCH_INVALID_INPUT_PARAM Invalid input parameter. TOUCH_INVALID_LIB_STATE Operation not allowed in the current touch library state. TOUCH_INVALID_SELFCAP_CONFIG_PARAM Invalid self capacitance configuration input parameter. TOUCH_INVALID_MUTLCAP_CONFIG_PARAM Invalid mutual capacitance configuration input parameter. TOUCH_INVALID_RECAL_THRESHOLD Invalid recalibration threshold input value. TOUCH_INVALID_CHANNEL_NUM Channel number parameter exceeded total number of channels configured. TOUCH_INVALID_SENSOR_TYPE Invalid sensor type. Sensor type must NOT be SENSOR_TYPE_UNASSIGNED. TOUCH_INVALID_SENSOR_ID Invalid sensor number parameter. TOUCH_INVALID_RS_NUM Number of rotor/sliders set as 0, while trying to configure a rotor/slider. TOUCH_INTERNAL_TOUCH_LIB_ERR Touch internal library error TOUCH_LOGICAL_PROGRAM_CNTR_FLOW_ERR Touch logical flow error TOUCH_LIB_CRC_FAIL Touch library data CRC error TOUCH_LIB_DI_CHECK_FAIL Touch library double inverse check field TOUCH_PC_FUNC_MAGIC_NO_1 Program counter magic number 1 TOUCH_PC_FUNC_MAGIC_NO_2 Program counter magic number 2 TOUCH_PC_FUNC_MAGIC_NO_3 Program counter magic number 3 TOUCH_PC_FUNC_MAGIC_NO_4 Program counter magic number 4 TOUCH_PINS_VALIDATION_FAIL Touch pins are not valid TOUCH_ALL_SENSORS_DISABLED All sensors are disabled TOUCH_CNFG_MISMATCH Number of sensors defined in DEF_XXXXCAP_NUM_SENSORS are not equal to the number of sensors configured using touch_xxxcap_sensor_config() or Number of moisture groups defined In DEF_XXXXCAP_NUM_MOIS_GROUPS are not equal to the number of groups configured using touch_xxxxcap_cnfg_mois_mltchgrp or If moisture group threshold is not configured for all moisture groups. 54 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 3.3.5 Sensor Channel (tag_channel_t) Detailed Description Sensor start and end channel type of a Sensor. Channel number starts with value 0. Data Fields CHANNEL_0 to CHANNEL_255 3.3.6 Touch Library State (tag_touch_lib_state_t) Detailed Description Touch library state. Data Fields TOUCH_STATE_NULL Touch library is un-initialized. All sensors are disabled. TOUCH_STATE_INIT Touch library has been initialized. TOUCH_STATE_READY Touch library is ready to start a new capacitance measurement on enabled sensors. TOUCH_STATE_CALIBRATE Touch library is performing calibration on all sensors. TOUCH_STATE_BUSY Touch library is busy with on-going capacitance measurement. 3.3.7 Sensor Type (tag_sensor_type_t) Detailed Description Sensor types available. Data Fields SENSOR_TYPE_UNASSIGNED Sensor is not configured yet. SENSOR_TYPE_KEY Sensor type key. SENSOR_TYPE_ROTOR Sensor type rotor. SENSOR_TYPE_SLIDER Sensor type slider. MAX_SENSOR_TYPE Max value of enum type for testing. 3.3.8 Touch Library Acquisition Mode (tag_touch_acq_mode_t) Detailed Description Touch library acquisition mode. Data Fields RAW_ACQ_MODE When raw acquisition mode is used, the measure_complete_callback function is called immediately once a fresh value of signals are available. In this mode, the Touch Library does not perform any post processing. So, the references, sensor states or rotor/slider position values are not updated in this mode. Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 55 NORMAL_ACQ_MODE When normal acquisition mode is used, the measure_complete_callback function is called only after the Touch Library completes processing of the signal values obtained. The references, sensor states and rotor/slider position values are updated in this mode. 3.3.9 AKS Group (tag_aks_group_t) Detailed Description It provides information about the sensors that belong to specific AKS group. NO_AKS_GROUP indicates that the sensor does not belong to any AKS group and cannot be suppressed. AKS_GROUP_x indicates that the sensor belongs to the AKS group x. Data Fields NO_AKS_GROUP AKS_GROUP_1 AKS_GROUP_2 AKS_GROUP_3 AKS_GROUP_4 AKS_GROUP_5 AKS_GROUP_6 AKS_GROUP_7 MAX_AKS_GROUP Max value of enum type for testing 3.3.10 Channel Gain Setting (tag_gain_t) Detailed Description A sensor detection hysteresis value. This is expressed as a percentage of the sensor detection threshold. HYST_x = hysteresis value is x% of detection threshold value (rounded down). Note: A minimum threshold value of 2 is used. Example: If detection threshold = 20, HYST_50= 10 (50% of 20) HYST_25 = 5 (25% of 20) HYST_12_5 = 2 (12.5% of 20) HYST_6_25= 2 (6.25% of 20 = 1, but value is hard limited to 2) Data Fields HYST_50 HYST_25 HYST_12_5 HYST_6_25 MAX_HYST Maximum value of enum type for testing 56 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 3.3.11 Sensor Recalibration Threshold (tag_recal_threshold_t) Detailed Description This is expressed as a percentage of the sensor detection threshold. RECAL_x = recalibration threshold is x% of detection threshold value (rounded down). Note: A minimum value of 4 is used. Example: If detection threshold = 40, RECAL_100 = 40 (100% of 40) RECAL_50 = 20 (50% of 40) RECAL_25 = 10 (25% of 40) RECAL_12_5 = 5 (12.5% of 40) RECAL_6_25 = 4 (6.25% of 40 = 2, but value is hard limited to 4) Data Fields RECAL_100 RECAL_50 RECAL_25 RECAL_12_5 RECAL_6_25 MAX_RECAL Maximum value of enum type for testing 3.3.12 Rotor Slider Resolution (tag_resolution_t) Detailed Description For rotors and sliders, the resolution of the reported angle or position. RES_x_BIT = rotor/slider reports x-bit values. Example: If slider resolution is RES_7_BIT, then reported positions are in the range 0..127. Data Fields RES_1_BIT RES_2_BIT RES_3_BIT RES_4_BIT RES_5_BIT RES_6_BIT RES_7_BIT RES_8_BIT MAX_RES Maximum value of enum type for testing 3.3.13 Auto Tune Setting (tag_auto_tune_type_t) Detailed Description Touch library PTC prescaler clock and series resistor auto tuning setting Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 57 Data Fields AUTO_TUNE_NONE Auto tuning mode disabled. This mode uses the user defined PTC prescaler and series resistor values. AUTO_TUNE_PRSC Auto tune PTC prescaler for best noise performance. This mode uses the user defined series resistor value. AUTO_TUNE_RSEL Auto tune series resistor for least power consumption. This mode uses the user defined PTC prescaler value. 3.3.14 PTC Clock Prescale Setting (tag_prsc_div_sel_t) Detailed Description Refer touch_configure_ptc_clock() API in touch.c. PTC Clock Prescale setting is available for each channel. Example: If generic clock input to PTC = 4 MHz, PRSC_DIV_SEL_1 sets PTC Clock to 4 MHz. PRSC_DIV_SEL_2 sets PTC Clock to 2 MHz. PRSC_DIV_SEL_4 sets PTC Clock to 1 MHz. PRSC_DIV_SEL_8 sets PTC Clock to 500 KHz. Data Fields PRSC_DIV_SEL_1 PRSC_DIV_SEL_2 PRSC_DIV_SEL_4 PRSC_DIV_SEL_8 3.3.15 PTC Series Resistor Setting (tag_rsel_val_t) Detailed Description For mutual capacitance mode, this series resistor is switched internally on the Y-pin. For self capacitance mode, the series resistor is switched internally on the sensor pin. PTC Series Resistance setting is available for individual channel. Example: RSEL_VAL_0 sets internal series resistor to 0 Ohms. RSEL_VAL_20 sets internal series resistor to 20 Kohms. RSEL_VAL_50 sets internal series resistor to 50 Kohms. RSEL_VAL_100 sets internal series resistor to 100 Kohms. Data Fields RSEL_VAL_0 RSEL_VAL_20 RSEL_VAL_50 RSEL_VAL_100 58 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 3.3.16 PTC Acquisition Frequency Delay Setting (freq_hop_sel_t) Detailed Description The PTC acquisition frequency is dependent on the generic clock input to PTC and PTC clock prescaler setting. This delay setting inserts n PTC clock cycles between consecutive measurements on a given sensor, thereby changing the PTC acquisition frequency. FREQ_HOP_SEL_1 setting inserts 0 PTC clock cycle between consecutive measurements. FREQ_HOP_SEL_16 setting inserts 15 PTC clock cycles. Hence, higher delay setting will increase the total time required for capacitance measurement on a given sensor as compared to a lower delay setting. An optimal setting avoids noise in the same frequency as the acquisition frequency. Data Fields FREQ_HOP_SEL_1 FREQ_HOP_SEL_2 FREQ_HOP_SEL_3 FREQ_HOP_SEL_4 FREQ_HOP_SEL_5 FREQ_HOP_SEL_6 FREQ_HOP_SEL_7 FREQ_HOP_SEL_8 FREQ_HOP_SEL_9 FREQ_HOP_SEL_10 FREQ_HOP_SEL_11 FREQ_HOP_SEL_12 FREQ_HOP_SEL_13 FREQ_HOP_SEL_14 FREQ_HOP_SEL_15 FREQ_HOP_SEL_16 3.3.17 PTC Acquisition Frequency Mode Setting (tag_freq_mode_sel_t) Detailed Description The frequency mode setting option enables the PTC acquisition to be configured for the following modes. Frequency hopping and spread spectrum disabled. Frequency hopping enabled with median filter. Frequency spread spectrum enabled without median filter. Frequency spread spectrum enabled with median filter. Range: FREQ_MODE_NONE (no frequency hopping & spread spectrum) to FREQ_MODE_SPREAD_MEDIAN (spread spectrum with median filter). Data Fields FREQ_MODE_NONE 0u FREQ_MODE_HOP 1u FREQ_MODE_SPREAD 2u FREQ_MODE_SPREAD_MEDIAN 3u Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 59 3.3.18 PTC Sensor Lockout Setting (nm_sensor_lockout_t) Detailed Description The sensor lockout setting option allows the system to be configured in the following modes. SINGLE_SENSOR_LOCKOUT Single sensor can be locked out. GLOBAL_SENSOR_LOCKOUT All the sensors are locked out for touch detection. NO_LOCK_OUT All the sensors are available for touch detection. Range: SINGLE_SENSOR_LOCKOUT to NO_LOCK_OUT. Data Fields SINGLE_SENSOR_LOCKOUT 0u GLOBAL_SENSOR_LOCKOUT 1u NO_LOCK_OUT 2u 3.3.19 Moisture Group Setting (moisture_grp_t) Detailed Description Sensor can be configured in the moisture group using this type. MOIS_DISABLED Indicates that the sensor does not belong to any moisture group. MOIS_GROUP_X Indicates that the sensor belongs to the moisture group x. Range: MOIS_DISABLED=0 to MOIS_GROUP_7. Data Fields MOIS_DISABLED=0 MOIS_GROUP_0 MOIS_GROUP_1 MOIS_GROUP_2 MOIS_GROUP_3 MOIS_GROUP_4 MOIS_GROUP_5 MOIS_GROUP_6 MOIS_GROUP_7 MOIS_GROUPN 3.3.20 Multi-touch Group Setting (mltch_grp_t) Detailed Description Sensor can be configured in the multi-touch group using this type MLTCH_NONE Indicates that the sensor does not belong to any multi-touch group. MLTCH_GROUP_X Indicates that the sensor belongs to the multi-touch group x. Range: MLTCH_NONE=0 to MOIS_GROUP_7. Data Fields MLTCH_NONE=0 MLTCH_GROUP_0 MLTCH_GROUP_1 MLTCH_GROUP_2 60 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 MLTCH_GROUP_3 MLTCH_GROUP_4 MLTCH_GROUP_5 MLTCH_GROUP_6 MLTCH_GROUP_7 MLTCH_GROUPN Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 61 3.4 Data Structures 3.4.1 Touch Library Configuration Type touch_config_t Struct Reference Touch library Input Configuration Structure. Data Fields Field Unit Description p_mutlcap_config touch_mutlcap_config_t p_selfcap_config touch_selfcap_config_t Pointer to mutual capacitance configuration structure. Pointer to self capacitance configuration structure. ptc_isr_lvl uint8_t PTC ISR priority level touch_mutlcap_config_t Struct Reference Touch Library mutual capacitance configuration input type. Data Fields 62 Field Unit Description num_channels uint16_t Number of channels. num_sensors uint16_t Number of sensors num_rotors_and_sliders uint8_t Number of rotors/sliders. global_param touch_global_param_t Noise measurement enable/disable touch_xxxxcap_acq_param touch_xxxxcap_acq_param_t Sensor acquisition parameter info. * p_data_blk uint8_t Pointer to data block buffer. buffer_size uint16_t Size of data block buffer. * p_mutlcap_xy_nodes uint16_t Pointer to xy nodes mutl_quick_reburst_enable uint8_t Quick re-burst enable (touch_filter_data_t *p_filter_data) void(* filter_callback ) Mutual capacitance filter callback enable_freq_auto_tune uint8_t Frequency auto tune enable enable_noise_measurement uint8_t Noise measurement enable nm_buffer_cnt uint8_t Memory allocation buffer mutl_mois_tlrnce_enable uint8_t Mutual capacitance moisture tolerance enable flag mutl_mois_groups uint8_t Number of mutual capacitance moisture groups Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 touch_selfcap_config_t Struct Reference Touch Library self capacitance configuration input type. Data Fields 3.4.2 Field Unit Description num_channels uint16_t Number of channels. num_sensors uint16_t Number of sensors num_rotors_and_sliders uint8_t Number of rotors/sliders. global_param touch_global_param_t Global sensor configuration information. touch_selfcap_acq_param touch_selfcap_acq_param_t Sensor acquisition parameter information. * p_data_blk uint8_t Pointer to data block buffer. buffer_size uint16_t Size of data block buffer. * p_selfcap_y_nodes uint16_t Pointer to selfcap nodes self_quick_reburst_enable uint8_t Quick re-burst enable (touch_filter_data_t *p_filter_data) void(* filter_callback ) Self capacitance filter callback enable_freq_auto_tune; uint8_t Frequency auto tune enable enable_noise_measurement uint8_t Noise measurement enable nm_buffer_cnt uint8_t Memory allocation buffer self_mois_tlrnce_enable uint8_t Self cap moisture tolerance enable flag self_mois_groups uint8_t Number of self-cap moisture groups Touch Library Safety Type touch_lib_fault_t Struct Reference Detailed Description This structure holds the inverse values of various touch library parameters. Data Fields Field Unit Description inv_touch_ret_status touch_ret_t Holds the inverse value of the touch return status. touch_lib_param_safety_t Struct Reference Detailed Description This structure holds the pointer to the data block for double inverse safety variables. Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 63 Data Fields 3.4.3 Field Unit Description *p_inv_channel_signals uint16_t Pointer to the channel signals which hold the inverse value of different channel signals. inv_acq_status touch_acq_status _t Holds the inverse value of the touch acquisition status. inv_num_channel_signals uint8_t Holds the inverse value of the total number of channel signals. inv_num_sensor_states uint8_t Holds the inverse value of the number of sensor states bytes. *p_inv_sensor_states uint8_t Pointer to the sensor states that holds the inverse value of different sensor states. inv_num_rotor_slider_values uint8_t Holds the inverse value of the number of rotor slider. *p_inv_rotor_slider_values uint8_t Pointer to the rotor slider values that holds the inverse value of different rotor slider values inv_lib_state uint8_t Holds the inverse value of the touch library state. p_inv_delta Int16_t Holds the inverse value of the touch delta. inv_current_time_ms uint16_t Holds the inverse value of current time millisecond variable. inv_burst_again uint8_t Holds the inverse value of the burst again flag. inv_acq_mode touch_acq_mode_t Holds the inverse value of the touch acquisition mode. inv_sf_ptc_error_flag uint8_t Holds the inverse value of the PTC error flag. inv_cc_cal_open_calibration_ vals uint16_t Holds the inverse value of the CC calibration value. *p_inv_sensor_noise_status uint8_t Holds the inverse value of the sensor noise status. *p_inv_sensor_mois_status uint8_t Holds the inverse value of the Sensor moisture status. *p_inv_chan_auto_os_status uint8_t Holds the inverse value of the channel auto os status. Touch Library Double Inverse Type touch_lib_di_data_block_t Struct Reference Detailed Description This structure holds the pointer to the data block for the double inverse safety variables. 64 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 Data Fields 3.4.4 Field Unit Description p_di_data_block uint8_t Holds the pointer to the data block allocated by the application for double inverse check for the safety variables. di_data_block_size uint16_t Holds the size of the data block allocated by the application of safety variables. Touch Library Parameter Type tag_touch_global_param_t Struct Reference Detailed Description Touch library global parameter type. Data Fields Field Unit Description di Sensor uint8_t Detect Integration (DI) limit. atch_drift_rate uint8_t Sensor away from touch drift rate. tch_drift_rate uint8_t Sensor towards touch drift rate. max_on_durationSensor uint8_t Maximum ON time duration. drift_hold_time uint8_t Sensor drift hold time. atch_recal_delay uint8_t Sensor away from touch recalibration delay. recal_threshold recal_threshold_t Sensor away from touch recalibration threshold. cal_seq_1_count uint8_t Sensor calibration dummy burst count. cal_seq_2_count uint8_t Sensor calibration settling burst count. auto_tune_sig_stability_l imit uint16_t Stability limit for frequency auto tune feature. auto_freq_tune_in_cnt uint8_t Frequency auto tune In counter. nm_sig_stability_limit uint16_t Stability limit for noise measurement. nm_noise_limit uint8_t Noise limit. nm_enable_sensor_lock_out nm_sensor_lockout_t Sensor lockout feature variable. nm_lockout_countdown uint8_t Lockout countdown for noise measurement. tag_touch_xxxxcap_param_t Struct Reference Detailed Description Touch library capacitance sensor parameter type. Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 65 Data Fields Field Unit Description aks_group aks_group_t Which AKS group, the sensor belongs to. detect_threshold threshold_t An unsigned 8-bit number setting a sensor detection threshold. detect_hysteresis hysteresis_t A sensor detection hysteresis value. This is expressed as a percentage of the sensor detection threshold. HYST_x = hysteresis value is x% of detection threshold value (rounded down). A minimum value of 2 is used. Example: If detection threshold = 20, HYST_50 = 10 (50% of 20) HYST_25 = 5 (25% of 20) HYST_12_5 = 2 (12.5% of 20) HYST_6_25 = 2 (6.25% of 20 = 1, but value is hard limited to 2) position_resolution resolution_t For rotors and sliders, the resolution of the reported angle or position. RES_x_BIT = rotor/slider reports x-bit values. Example: If slider resolution is RES_7_BIT, then reported positions are in the range 0..127 position_hysteresis uint8_t Sensor position hysteresis. This is valid only for a rotor or slider. bits 1..0: hysteresis. This parameter is valid only for mutual cap. tag_touch_xxxxcap_acq_param_t Struct Reference Detailed Description Capacitance sensor acquisition parameter type. Data Fields 66 Field Unit Description p_xxxxcap_gain_per_node gain_t Pointer to gain per node. touch_xxxxcap_freq_mode uint8_t Setup acquisition frequency mode. p_xxxxcap_ptc_prsc prsc_div_sel_t Pointer to PTC clock prescaler value per node. p_xxxxcap_resistor_value rsel_val_t Pointer to PTC series resistor value per node. p_xxxxcap_hop_freqs freq_hop_sel_t Pointer to acquisition frequency settings. p_xxxxcap_filter_level filter_level_t Pointer to Filter level per node.. p_xxxxcap_auto_os auto_os_t Pointer to Auto oversampling per node. p_xxxxcap_ptc_prsc_cc_cal prsc_div_sel_t Pointer to PTC clock prescale value during CC cal p_xxxxcap_resistor_value_ cc_cal rsel_val_t Pointer to PTC series resistor value during CC cal.. Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 3.4.5 Touch Library Measurement Data Type tag_touch_measure_data_t Struct Reference Detailed Description Touch library measurement parameter type. Data Fields 3.4.6 Field Unit Description measurement_done_touch volatile uint8_t Flag set by touch_xxxxcap_measure_complete_callback( ) function when a latest Touch status is available. acq_status touch_acq_status_t Status of touch measurement. num_channel_signals uint16_t Length of the measured signal values list. *p_channel_signals uint16_t Pointer to measured signal values for each channel. num_channel_references uint16_t Length of the measured reference values list. * p_channel_references uint16_t Touch status of each sensor. num_sensor_states uint8_t Number of sensor state bytes. num_rotor_slider_values uint8_t Length of the rotor and slider position values list. *p_rotor_slider_values uint8_t Pointer to rotor and slider position values. num_sensors uint16_t Length of the sensors data list. * p_cc_calibration_vals uint16_t Pointer to calibrated compensation values for a given sensor channel. p_sensors sensor_t Pointer to sensor data. *p_sensor_noise_status uint8_t Pointer to noise status of the sensors. *p_nm_ch_noise_val uint16_t Pointer to noise level value of each channel. p_sensor_mois_status uint8_t Pointer to moisture status. * p_auto_os_status uint8_t Pointer to Per channel Auto Oversample status. Touch Library Filter Data Type tag_touch_filter_data_t Struct Reference Detailed Description Touch library filter data parameter type. Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 67 Data Fields 3.4.7 Field Unit Description num_channel_signals uint16_t Length of the measured signal values list. p_channel_signals uint16_t Pointer to measured signal values for each channel. Touch Library Time Type tag_touch_time_t Struct Reference Detailed Description Touch library time parameter type. Data Fields 3.4.8 Field Unit Description measurement_period_ms uint16_t Touch measurement period in milliseconds. This variable determines how often a new touch measurement must be done. current_time_ms volatile uint16_t Current time, set by timer ISR. mutl_time_to_measure_touch volatile uint8_t Flag set by timer ISR when it is time to measure touch - Mutual capacitance method. self_time_to_measure_touch volatile uint8_t Flag set by timer ISR when it is time to measure touch - Self capacitance method. Field Unit Description tlib_state touch_lib_state_t Touch library state. num_channels_in_use uint16_t Number of channels currently in use. num_sensors_in_use uint16_t Number of sensors in use irrespective of the sensor is enable or disable. num_rotors_sliders_in_use uint8_t Number of rotor sliders in use, irrespective of the rotor/slider being disabled or enabled. max_channels_per_rotor_slider uint8_t Max possible number of channels per rotor or slider. fw_version uint16_t Touch library version. Touch Library Info Type tag_touch_info_t Struct Reference Detailed Description Touch library Info type. Data Fields 68 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 3.4.9 Touch Library Version touch_libver_info_t Struct Reference Detailed Description Touch library version information. Product id for Safety Library is 202. Firmware version is formed of major, minor and patch version as given below: TLIB_MAJOR_VERSION = 5 TLIB_MINOR_VERSION = 1 TLIB_PATCH_VERSION = 4 fw_version = (TLIB_MAJOR_VERSION << 8) | (TLIB_MINOR_VERSION << 4) | (TLIB_PATCH_VERSION ) Data Fields Field Unit Description chip_id uint32 Chip identification number. product_id uint16_t Product identification number. fw_version uint16_t Library version number. 3.5 Global Variables 3.5.1 touch_lib_fault_test_status Type touch_lib_fault_t Detailed Description This structure holds the inverse value of the touch return status. 3.5.2 touch_error_app_cb Type void (*)(touch_ret_t lib_error) Detailed Description Callback function pointer that must be initialized by the application before a touch library API is called. Touch library would call the function pointed by this variable under certain error conditions. 3.5.3 touch_suspend_app_cb Type void (* volatile touch_suspend_app_cb) (void) Detailed Description Callback function pointer that must be initialized by the application before a touch library API is called.Touch library would call the function pointed by this function when suspension operation has to be carry on by the application. Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 69 If suspend operation is requested by application and touch library is not in TOUCH_STATE_BUSY state, then application will not receive suspend callback from the library. The application should continue the suspend operation in that case without waiting for the suspend callback. 3.6 Functions 3.6.1 Touch Library Initialization The following API is used to initialize the Touch Library with capacitance method pin, register and sensor configuration provided by the user. touch_ret_t touch_xxxxcap_sensors_init (touch_config_t * p_touch_config) Fields Description p_touch_config Pointer to touch configuration structure. Returns: touch_ret_t: Touch Library status. 3.6.2 Touch Library Sensor Configuration The following API configures a capacitance sensor of type key, rotor or slider. touch_ret_t touch_xxxxcap_sensor_config (sensor_type_t sensor_type, channel_t from_channel, channel_t to_channel, aks_group_t aks_group, threshold_t detect_threshold, hysteresis_t detect_hysteresis, resolution_t position_resolution, uint8_t position_hysteresis, sensor_id_t * p_sensor_id) Fields Description sensor_type Sensor type key, rotor or slider. from_channel First channel in the slider sensor. to_channel Last channel in the slider sensor. aks_group AKS group (if any) the sensor belongs to. detect_threshold Sensor detection threshold. detect_hysteresis Sensor detection hysteresis value. position_resolution Resolution of the reported position value. position_hysteresis Hysteresis level of the reported position value. p_sensor_id Sensor id value of the configured sensor is updated by the Touch Library. Returns: touch_ret_t: Touch Library status. 3.6.3 Touch Library Sensor Calibration The following API is used to calibrate the capacitance sensors for the first time before starting a touch measurement. This API can also be used to force calibration of capacitance sensors during runtime. 70 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 touch_ret_t touch_xxxxcap_sensors_calibrate (auto_tune_type_t auto_tune_type ) Fields Description auto_tune_type Specify auto tuning parameter mode. Returns: touch_ret_t: Touch Library status. Note: Call touch_xxxxcap_sensors_measure API after executing this API. The following API calibrates the single sensor. touch_ret_t touch_xxxxcap_calibrate_single_sensor(sensor_id_t sensor_id) Fields Description sensor_id Sensor number to calibrate. Returns: touch_ret_t: Touch Library status. Note: Call touch_xxxxcap_sensors_measure API after executing this API. If calibration of a disabled sensor is required, touch_xxxxcap_sensor_reenable API should be used with calibration option. touch_xxxxcap_calibrate_single_sensor API should not be used for calibrating a disabled sensor. Otherwise it may lead to TOUCH_LOGICAL_PROGRAM_CNTR_FLOW_ERR. 3.6.4 Touch Library Sensor Measurement The following API starts a touch measurement on capacitance sensors. touch_ret_t touch_xxxxcap_sensors_measure (touch_current_time_t current_time_ms,touch_acq_mode_t xxxxcap_acq_mode, uint8_t(*measure_ complete_callback)(void)) Fields Description current_time_ms Current time in millisecond. xxxxcap_acq_mode Normal or raw acquisition mode. measure_complete_callback Callback function to indicate that a single touch measurement is completed. Returns: touch_ret_t: Touch Library status. 3.6.5 Touch Library Sensor Specific Touch Delta Read The following API can be used retrieve the delta value corresponding to a given sensor for capacitance sensors respectively. Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 71 touch_ret_t touch_xxxxcap_sensor_get_delta (sensor_id_t sensor_id, touch_delta_t * p_delta) Fields Description sensor_id The sensor id for which delta value is being seeked. p_delta Pointer to the delta variable to be updated by the touch library. Returns: touch_ret_t: Touch Library status. 3.6.6 Touch Library Sensor Specific Parameter Configuration Read-write The following API sets the individual sensor specific configuration parameters for capacitance sensors. touch_ret_t touch_xxxxcap_sensor_update_config touch_xxxxcap_param_t * p_touch_sensor_param) (sensor_id_t Fields Description p_sensor_id The sensor id for which configuration parameter information is being set. p_touch_sensor_param The touch sensor parameter structure that will be used by the touch library to update. sensor_id, Returns: touch_ret_t: Touch Library status. The following API reads the sensor configuration parameters for capacitance sensors. touch_ret_t touch_xxxxcap_sensor_get_config touch_xxxxcap_param_t * p_touch_sensor_param) (sensor_id_t Fields Description p_sensor_id The sensor id for which configuration parameter information is being set. p_touch_sensor_param The touch sensor parameter structure that will be used by the touch library to update. sensor_id, Returns: touch_ret_t: Touch Library status. 3.6.7 Touch Library Sensor Specific Acquisition Configuration Read-write The following API sets the sensor specific acquisition configuration parameters for capacitance sensors respectively. 72 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 touch_ret_t touch_xxxxcap_sensor_update_acq_config (touch_xxxxcap_acq_param_t * p_touch_xxxxcap_acq_param) Fields Description p_touch_xxxxcap_acq _param The touch sensor acquisition parameter structure that will be used by the touch library to update. Returns: touch_ret_t: Touch Library status. Note: touch_xxxxcap_sensor_update_acq_config API must be called after the touch_xxxxcap_sensors_init API. The following API gets the sensor specific acquisition configuration parameters for cap sensors respectively. touch_ret_ttouch_xxxxcap_sensor_get_acq_config (touch_xxxxcap_acq_param_t * p_touch_xxxxcap_acq_param) Fields Description p_touch_xxxxcap_acq _param The touch sensor acquisition parameter structure that will be used by the touch library to update. Returns: touch_ret_t: Touch Library status. 3.6.8 Touch Library Sensor Global Parameter Configuration Read-write The following API updates the global parameter for cap sensors respectively. touch_ret_t touch_xxxxcap_update_global_param (touch_global_param_t * p_global_param) Fields Description p_global_param The pointer to global sensor configuration. Returns: touch_ret_t: Touch Library status. Note: touch_xxxxcap_update_global_param API must be called after the touch_xxxxcap_sensors_init API. The following API reads back the global parameter for cap sensors respectively. touch_ret_t touch_xxxxcap_get_global_param (touch_global_param_t * p_global_param) Fields Description p_global_param The pointer to global sensor configuration. Returns: Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 73 touch_ret_t: Touch Library status. 3.6.9 Touch Library Info Read The following API gets the Touch Library status information for cap sensors respectively. touch_ret_t touch_xxxxcap_get_libinfo (touch_info_t * p_touch_info) Fields Description p_touch_info Pointer to the touch info data structure that will be updated by the touch library. Returns: touch_ret_t: Touch library status. 3.6.10 Touch Library Program Counter touch_ret_t touch_lib_pc_test_magic_no_1 (void) The following API tests the program counter inside the touch library. This function returns the unique magic number TOUCH_PC_FUNC_MAGIC_NO_1 to the application. Returns: touch_ret_t touch_ret_t touch_lib_pc_test_magic_no_2 (void) This function tests the program counter inside the touch library. This function returns the unique magic number TOUCH_PC_FUNC_MAGIC_NO_2 to the application. Returns: touch_ret_t touch_ret_t touch_lib_pc_test_magic_no_3 (void) This function tests the program counter inside the touch library.This function returns the unique magic number TOUCH_PC_FUNC_MAGIC_NO_3 to the application. Returns: touch_ret_t touch_ret_t touch_lib_pc_test_magic_no_4 (void) This function tests the program counter inside the touch library.This function returns the unique magic number TOUCH_PC_FUNC_MAGIC_NO_4 to the application. Returns: touch_ret_t 3.6.11 Touch Library CRC Configuration Check touch_ret_t touch_calc_xxxxcap_config_data_integrity This function computes 16 bit CRC for the touch configuration data and stores it in a global variable internal to the library. Returns: touch_ret_t. touch_ret_t touch_test_xxxxcap_config_data_integrity(void) This function performs a test to verify the integrity of the touch configuration data. It computes the CRC value and tests it against the previously stored CRC value. The result of the comparison is passed back to the application. 74 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 Returns: Returns the result of the test integrity check. If CRC check passes, it returns TOUCH_SUCCESS, else it returns TOUCH_LIB_CRC_FAIL. 3.6.12 Touch Library Double Inverse check touch_ret touch_xxxxcap_di_init (touch_lib_di_data_block_t *p_dblk) This function initializes the memory from inverse data block allocated by the application for different pointers in the touch_lib_param_safety_t. Data Fields Fields Description * p_dblk Pointer to the starting address of the data block allocated by the application for double inverse check. Returns: touch_ret_t This API must be called after the touch_xxxxcap_sensors_init API and before any other API is called. 3.6.13 Touch Library Enable Disable Sensor touch_ret touch_xxxxcap_sensor_disable (sensor_id_t sensor_id) This function disable the sensor. Data Fields Fields Description sensor_id Sensor which needs to be disabled. Returns : touch_ret_t touch_ret touch_xxxxcap_sensor_reenable (sensor_id_t sensor_id, uint8_t no_calib) This function will enable the sensor. Data Fields Fields Description sensor_id Sensor which needs to be re-enabled. no_calib Re-enable of sensor would be done with calibration or not. If value is 1, sensor would be re-enable without calibration else if value is 0, sensor would be re-enable with calibration. Returns : touch_ret_t Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 75 Notes: 1. Call touch_xxxxcap_sensors_measure API after executing this API. 2. It is recommended to re-enable the sensors with calibration (no_calib = 0), if sensors are re-enabled after a long duration. Refer Section 2.18, “Drifting on Disabled Sensors”. 3.6.14 Touch Library Version Information This function will provide the library version information. touch_ret_t touch_library_get_version_info(touch_libver_info_t *p_touch_libver_info ); Data Fields Fields Description p_touch_libver_info Pointer to touch library version information structure. Returns : touch_ret_t 3.6.15 Touch Library Moisture Tolerance This function can be used to Configure sensor in the moisture group and multi touch group. touch_ret_t touch_xxxxcap_cnfg_mois_mltchgrp (sensor_id_t snsr_id,moisture_grp_t mois_grpid,mltch_grp_t mltch_grpid); 76 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 Data Fields Fields Description snsr_id Sensor to configure. mois_grpid Sensor to be configured in this moisture group. mltch_grpid Sensor to be configured in this multi touch group. Returns : touch_ret_t This function can be used to configure moisture group sensor moisture lock and system moisture lock threshold. touch_ret_t touch_xxxxcap_cnfg_mois_threshold (moisture_grp_t,mois_snsr_threshold_t snsr_threshold,mois_system_threshold_t system_threshold); Data Fields Fields Description mois_grpid Moisture group id. snsr_threshold Sensor moisture lock threshold. system_threshold System moisture lock threshold. Returns : touch_ret_t This function can be used to enable the moisture tolerance feature. touch_ret_t touch_xxxxcap_mois_tolrnce_enable (void); Data Fields None Returns : touch_ret_t This function can be used to disable the moisture tolerance feature. touch_ret_t touch_xxxxcap_mois_tolrnce_disable (void); Data Fields None Returns : touch_ret_t 3.6.16 Touch PTC Peripheral Enable Disable touch_ret_t touch_disable_ptc(void) This function disable the PTC module Data Fields Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 77 None Returns : touch_ret_t Note: Refer Section 2.17 and Section 4.6 for use cases associated with touch_disable_ptc. touch_ret_t touch_enable_ptc(void) This function enable the PTC module. Data Fields None Returns : touch_ret_t Note: Refer Section 2.17 for use cases associated with touch_enable_ptc. 3.6.17 Touch Library Suspend Resume touch_ret_t touch_suspend_ptc(void) This function suspends the PTC library’s current measurement cycle. The completion of the operation is indicated through callback pointer that must be initialized by the application. Refer section Section 3.5.3 and Section 2.17. Data Fields None Returns : touch_ret_t touch_ret_t touch_resume_ptc(void) This function resumes the PTC library’s current measurement which was suspended using touch_suspend_ptc. After the touch_resume_ptc is called by the application, the touch_xxxxcap_sensors_measure API should be called only after the measurement complete callback function is received. Refer section Section 3.5.3 and Section 2.17. Data Fields None Returns : touch_ret_t Note: The APIs related to touch suspend operation must be used in accordance with the safety requirements of the product and must be taken care by the customer application. 3.6.18 Touch Library Re-Initialization touch_ret_t touch_xxxxcap_sensors_deinit(void) This function deinitializes the touch library.This API should be called only when the library state is in TOUCH_STATE_INIT or TOUCH_STATE_READY state. After calling deinit API,no other API should be called apart from touch_xxxxcap_sensors_init to reinitialize the touch library. Data Fields None Returns : touch_ret_t Note: 78 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 a. If one module(self-cap or mutual-cap touch library) is de-initialized, then all other modules should be deinitialized as well. For eg., if mutual-cap touch library is de-initialized, then mutual-cap FMEA, self-cap touch library and self-cap FMEA should be de-initialized or stopped. b. When touch library or FMEA has to be re-initialized, the application has to follow the initialization sequence as done during power-up. Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 79 4. FMEA This section provides information about the FMEA component. The FMEA library supports the rotor/slider built with spatially interpolated design. FMEA component is further categorized into mutual and self capacitance FMEA component. FMEA will be performed on all the touch pins including sensor disabled pins. For more information about designing the touch sensor, refer to Buttons, Sliders and Wheels Touch Sensor Design Guide (www.atmel.com). 4.1 Double Inverse Memory Check 4.1.1 Application to FMEA No variable is interfaced from the application to FMEA. Hence, Double Inverse mechanism need not be used for protection. 4.1.2 FMEA to Application The following variable must be protected using the specified inverse variable. Table 4-1. Variable Inverse Variable faults_to_report faults_to_report_inv (Refer Section 5.3.3) 4.2 Memory Requirement The following table provides the Flash and the RAM memory required for various configurations using different number of channels. Default Configuration: The following Macros are defined for all the cases mentioned for the Memory Calculation in Section 4.2.1 SELFCAP_FMEA_MAP_FAULT_TO_CHANNEL MUTLCAP_FMEA_MAP_FAULT_TO_CHANNEL 4.2.1 Memory Requirement for IAR Library 4.2.1.1 Memory Requirement for Mutual Capacitance Total No of Mutual Cap Channels Total Code Memory 1 2224 88 10 2268 108 20 2268 124 40 2268 164 256 2300 596 80 Total Data Memory Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 4.2.1.2 Memory Requirement Self Capacitance Total No of Self Cap Channels Total Code Memory 1 2056 80 2 2124 84 11 2148 124 16 2174 144 Total Data Memory 4.2.1.3 e Total No of Mutual Cap Channels Total No of Self Cap Channels Total Code Memory Total Data Memory 1 1 4538 168 40 8 4689 276 80 11 4692 368 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 81 4.3 API Execution Time 4.3.1 Mutual Capacitance API Execution Time The following table provides information about the execution time required for various FMEA APIs. System Clock Frequency: 48MHz PTC Clock Frequency: 4MHz Table 4-2. Mutual Capacitance FMEA API Execution Time API Input Value Time (in µs) 1 Channel (PORT A) 20 Channels (PORT A & B) (5 x4) sf_mutlcap_fmea_in it sf_mutlcap_fmea_te st sf_mutlcap_fmea_te st_open_pins_per_c hannel Any value 84.8 125.6 0x01 (short to Vcc) 114 303.5 0x02 (short to Vss) 115.2 309 0x04 (short between pins) 744 3656 0x08 (PTC register test) 214 352.9 0x10 (input configuration data integrity check) 122 265.1 0x1F (all test) 1000 4032 Any value 13200 12830 Notes: 1. For the sf_mutlcap_fmea_test_open_pins_per_channel API, the preceding table provides the maximum time required to complete the procedure. After the control is returned back to the application, the application can execute any other tasks. 2. API Execution Time marked as * are calculated for sensors with typical sensor capacitance values. The time for the Mutual capacitance FMEA API to return the control to the application is as follows: API Input Value Time (in µs) 1 Channel (PORT A) 20 Channels (PORT A & B) (5 x4) sf_mutlcap_fmea_test_ope n_pins_per_channel 82 Any value 50.2 50.3 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 4.3.2 Self Capacitance API Execution Time The following table provides information about the APIs and their corresponding execution time. Table 4-3. Self Capacitance FMEA API Execution Time API Input Value Time (in µs) 1 Channel (PORT A) sf_selfcap_fmea_init sf_selfcap_fmea_test sf_selfcap_fmea_test_ope n_pins_per_channel 16 Channels (PORT A & B) Any value 79.4 218 0x01 (short to Vcc) 99.4 290 0x02 (short to Vss) 99.8 298 0x04 (short between pins) 612 3540 0x08 (PTC register test) 212 348 0x10 (input configuration data integrity check) 116 329 0x1F (all test) 848 3946 Any value 10800 10700 Notes: 1. For the sf_selfcap_fmea_test_open_pins_per_channel API, the preceding table provides the maximum time required to complete the procedure. After the control is returned back to the application, the application can execute any other tasks. 2. API Execution Time marked as * are calculated for sensors with typical sensor capacitance values. The time for the Self capacitance FMEA API to return the control to the application is as follows: Table 4-4. Self Capacitance FMEA Asynchronous API Execution Time API Input Value Time (in µs) 1 Channel sf_selfcap_fmea_test_ope n_pins_per_channel Any value 16 Channels (PORT A) (PORT A & B) 48.7 48.9 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 83 4.4 Error Interpretation Table 4-5. Error Interpretation List of API sf_xxxxcap_fmea_ini t sf_xxxxcap_fmea_tes t Error Bit Reason FMEA_ERR_INIT CRC value computed by touch library has failed double inverse check Not applicable FMEA_ERR_INIT Input pointer is NULL Not applicable FMEA_ERR_INIT Input values are not within limit Not applicable FMEA_ERR_PRE_TEST Undefined test bits are set Not applicable FMEA_ERR_PRE_TEST This function is called before calling sf_xxxxcap_fmea _init() Not applicable FMEA_ERR_SHORT_TO_V CC Any one touch pin is short to Vcc FMEA_ERR_CONFIG_CHE CK CRC CRC check has failed Not applicable FMEA_ERR_SHORT_TO_V SS Any one touch pin is short to Vss FMEA_ERR_SHORT_TO_P INS Any two touch pins are shorted to each other FMEA_ERR_PTC_REG PTC register test failed or the PTC test status returned by touch library failed double inverse check FMEA_ERR_SHORT_TO_VCC FMEA_ERR_SHORT_TO_VSS FMEA_ERR_SHORT_TO_PINS At least one test has failed FMEA_ERR_PTC_REG FMEA_ERR_CONFIG_CHECK 84 Error Coverage Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 XXXXCAP enabled pins Not applicable XXXXCAP enabled pins XXXXCAP enabled pins Not applicable Table 4-5. Error Interpretation List of API sf_xxxxcap_fmea_tes t_open_pins_per_cha nnel 4.5 Error Bit Reason Error Coverage FMEA_ERR_PRE_TEST This function is called before calling sf_xxxxcap_fmea_ init() Not applicable FMEA_ERR_PRE_TEST Channel number passed is more than the maximum possible Not applicable FMEA_ERR_OPEN_PINS There is a disconnect between sensor electrode and device pin for the given channel number One channel per call Data and Function Protection The functions and global variables which are used only by FMEA are marked as static. The user / application should not change the same to non-static. The header file sf_fmea_samd_int.h file is used only by FMEA. The user/application should not include this header file in any other files. Table 4-6. Header File Availability for Application Header File Availability for Application sf_fmea_samd_int.h sf_fmea_samd_api.h 4.6 No Configurable Fields Not applicable FMEA_VAR_LOCATION MUTLCAP_FMEA_MAP_FAULT_TO_CH ANNEL SELFCAP_FMEA_MAP_FAULT_TO_CH ANNEL Yes FMEA Considerations FMEA Short Between Pins, Short to VSS, Short to VCC can be detected on the MCU pins. The periodicity of Short to VSS test should be much lesser than the Short between Pins test. The touch_disable_ptc could be called after sf_xxxxcap_fmea_test API and also after the open pin test callback is received for each channel.This should be done to reduce the power consumption. Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 85 5. FMEA API 5.1 Typedefs None 5.2 Enumerations 5.2.1 sf_fmea_faults_t This enumeration describes the types of FMEA faults or errors such as short to Vcc, short to Vss, and short between pins that occur in a system. The test results of FMEA tests are stored in global fault report structure. The generic test result of FMEA test is stored in faults_to_report field of sf_xxxxcap_fmea_fault_report_var. Each bit of the field faults_to_report field represents the test status for each FMEA test. Table 5-1. FMEA Fault Details Values Description FMEA_ERR_SHORT_TO_VCC Short to Vcc FMEA_ERR_SHORT_TO_VSS Short to Vss FMEA_ERR_SHORT_TO_PINS Short between pins FMEA_ERR_PTC_REG PTC register test FMEA_ERROR_CONFIG_CHECK Checks the input configuration integrity FMEA_ERR_OPEN_PINS Open connection between device pin and sensor FMEA_ERROR_PRE_TEST Pre-test failure FMEA_ERR_INIT Initialization For example, FMEA_ERR_SHORT_TO_VCC bit represents short to Vcc test status, the FMEA_ERR_SHORT_TO_VSS bit represents short to Vss test status. Note: If multiple FMEA tests are conducted in a single API call, sf_xxxxcap_fmea_fault_report_var will hold the consolidated results of all the requested tests. In other case, when FMEA tests are conducted one after other by the application, sf_xxxxcap_fmea_fault_report_var will hold only the latest test results(previous results will be cleared each time by FMEA component).In such cases, it is recommenced that application should keep track of fault report variable. 86 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 5.3 Data Structures 5.3.1 sf_xxxxcap_fmea_open_test_config_t The configuration parameters required for FMEA open pin test are passed through this structure. Fields Type Description uint16_t CC value should be provided for each selfcap channel.In case of mutual cap, single cc calibration value needs to be provided. cc_cal_valid_min_val For Mutual capacitance cc_cal_valid_min_val[DEF_ SELFCAP_NUM_CHANNELS] Maximum value: 16000 For Self capacitance Open errors are declared only if CC calibration values of a particular channel is out of range in N1 samples out of N2 samples. For example, if N2 is set to 4 and N1 is set to 2, then CC calibration values are compared with the cc_cal_valid_min_val low and high limits, for continuous 4 samples. The channels whose CC calibration values are in error for more than 2 samples are declared error. cc_cal_val_min_no_error Whenever an open pin test function is called, a sample counter corresponding to the channel is incremented. If an error is found among the samples, the error count for the channel is incremented. If the error count reaches N1, the error is reported and the error count and sample count are reset. If sample count reaches N2 value (it indicates that the error count has not reached N1) the error count and sample count is reset. uint8_t In the previous example, cc_cal_val_min_no_error represents N1. Maximum value: cc_cal_val_no_of_samples Minimum value: 1 In the previous example, cc_cal_val_no_of_samples represents N2. cc_cal_val_no_of_samples uint8_t Maximum value: 15 Minimum value: 1 xxxxcap_open_pin_test_cal lback void (*)(uint16_t) After completing the open pin test, the open pin test function calls the xxxxcap_open_pin_test_callback function and indicates the completion of the open pin test. The application can pick the test status in this complete callback functions. Note: The open pin test is performed indirectly by measuring the capacitance of the sensor electrode. If the sensor electrode is disconnected from the device pin, the measured capacitance value will be less when compared to that of the sensor electrode connected to the device pin. Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 87 During design stage, the application developer must monitor the equivalent capacitance value for all the channels under normal (all the sensors are connected and un-touched) condition. User can read the equivalent capacitance value as shown in the following example: /* channel 0’s equivalent capacitance */ p_xxxxcap_measure_data->p_cc_calibration_vals[0] /* channel 1’s equivalent capacitance */ p_xxxxcap_measure_data->p_cc_calibration_vals[1] Although not mandatory, it is recommended to set cc_cal_valid_min_val as 30% of the lowest value observed in p_cc_calibration_vals array. For example, if 415 is the lowest value observed in the p_cc_calibration_vals array, set cc_cal_valid_min_val as 124. Note: The CC values would differ based on the value of series resistance (internal or external) connected to the touch pins. 5.3.2 sf_xxxxcap_fmea_input_config_t The Open CC values will change based on the resistance added on the touch lines.Proper value of CC has to given as input to the sf_xxxxcap_fmea_test_open_pins_per_channel function. The FMEA test input configuration data are passed through this structure. typedef struct tag_sf_xxxxcap_fmea_input_config_t { sf_xxxxcap_fmea_open_test_config_t *xxxxcap_open_test_config; }sf_xxxxcap_fmea_input_config_t; Values xxxxcap_open_test_config 5.3.3 Description Refer sf_xxxxcap_fmea_open_test_config_t description in Section 5.3.1 sf_mutlcap_fmea_fault_report_t The Mutual capacitance FMEA test API status is updated in this structure. typedef struct tag_sf_mutlcap_fmea_fault_report_t { uint16_t faults_to_report; uint16_t faults_to_report_inv; uint16_t x_lines_fault_vcc; uint16_t y_lines_fault_vcc; uint16_t x_lines_fault_vss; uint16_t y_lines_fault_vss; uint16_t x_lines_fault_short; uint16_t y_lines_fault_short; #ifdef MUTLCAP_FMEA_MAP_FAULT_TO_CHANNEL uint8_t fmea_channel_status[DEF_MUTLCAP_NUM_CHANNELS]; 88 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 #endif }sf_mutlcap_fmea_fault_report_t; Values Description If a bit is set to 1 in fault_to_report, then corresponding fault has occurred. If a bit is set to 0 in fault_to_report, then the corresponding fault has not occurred. The X/Y lines and channels that are affected are provided in other fields. FMEA fault status Bit 0 represents the short to Vcc. Bit 1 represents the short to Vss. Bit 2 represents the short to PINS. Bit 3 represents the PTC register test. Bit 4 represents the Configuration data integrity. Bit 5 represents the Open pin fault. Bit 6 represents the fault pre-test failure condition. Bit 7 represents the fault init failed condition. The bit 0 is set if at least one of the touch pin (X or Y) is short to Vcc. The bit 1 is set if at least one of the touch pin (X or Y) is short to Vss. The bit 2 is set if at least two touch pins are shorted to each other. faults_to_report The bit 3 is set if, a fault is found in PTC register test the test result passed by touch library fails double inversion check The bit 4 is set if, a fault is found in the input configuration data integrity the CRC value computed by touch library fails double inversion check The bit 5 is set if at least one touch pin is not connected with the sensor electrode. The bit 6 is set if, the sf_mutlcap_fmea_test() function is called before executing the initialization function if the channel number passed to sf_mutlcap_fmea_test_open_pins_per_channel() function is greater than DEF_MUTLCAP_NUM_CHANNELS. The bit 7 is set if, invalid parameters are passed to the FMEA initialization function when the CRC value computed by the touch library for the input configuration data fails the double inverse check the input pointer is NULL. faults_to_report_inv Compliment value of field faults_to_report x_lines_fault_vcc If bit n is set, then Xn pin is short to Vcc y_lines_fault_vcc If bit n is set, then Yn pin is short to Vcc Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 89 Values Description x_lines_fault_vss If bit n is set, then Xn pin is short to Vss y_lines_fault_vss If bit n is set, then Yn pin is short to Vss y_lines_fault_short If bit n is set, then Xn pin is short to other touch pin x_lines_fault_short If bit n is set, then Yn pin is short to other touch pin This array maps FMEA faults to individual channel numbers. This variable is applicable only if MUTLCAP_FMEA_MAP_FAULT_TO_CHANNEL macro is defined in sf_fmea_samd_api.h file. This is used to map FMEA faults to individual channel numbers. Each byte in the array corresponds to the FMEA faults in the particular channel number. Example: FMEA_CHANNEL_STATUS[0] represents the fault of the channel number 0. Each bit in the byte represents the FMEA test status. Example: fmea_channel_status [DEF_MUTLCAP_NUM_CHANN ELS] Bit 0 represents the short to Vcc. Bit 1 represents the short to Vss. Bit 2 represents the short to PINS. Bit 5 represents the open pin fault. If X or Y pin corresponding to a channel is shorted to Vcc then the Bit 0 position of that specific byte will be set to 1. If X or Y pin corresponding to the channel is shorted to Vss then the Bit 1 position of that specific byte will be set to 1. If X or Y pin corresponding to the channel is shorted to other X or Y pins, the Bit 2 of all the channel which uses the faulty X or Y will be set to 1. Bit 5 of all the channels whose sensor electrode is not connected to the device pin is set to 1. Since PTC register test, configuration data integrity, pre-test failure and initialization failure are common for all the channels, fmea_channel_status will not contain those information. 5.3.4 sf_selfcap_fmea_fault_report_t The self capacitance FMEA test API status is updated in this structure. typedef struct tag_sf_selfcap_fmea_fault_report_t { uint16_t faults_to_report; uint16_t faults_to_report_inv; uint16_t y_lines_fault_vcc; uint16_t y_lines_fault_vss; uint16_t y_lines_fault_short; #ifdef SELFCAP_FMEA_MAP_FAULT_TO_CHANNEL uint8_t fmea_channel_status[DEF_SELFCAP_NUM_CHANNELS]; #endif 90 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 }sf_selfcap_fmea_fault_report_t; Values Description If a bit is set to 1 in fault_to_report, then corresponding fault has occurred. If a bit is set to 0 in fault_to_report, then the corresponding fault has not occurred. The Y lines and channels that are affected are provided in other fields. FMEA fault status: Bit 0 represents the short to Vcc. Bit 1 represents the short to Vss. Bit 2 represents the short to PINS. Bit 3 represents the PTC register test. Bit 4 represents the Configuration data integrity. Bit 5 represents the Open pin fault. Bit 6 represents the fault pre-test failure condition. Bit 7 represents the fault init failed condition. The bit 0 is set if at least one of the touch pin (Y) is short to Vcc. The bit 1 is set if at least one of the touch pin (Y) is short to Vss. The bit 2 is set if at least two touch pins are shorted to each other. faults_to_report The bit 3 is set if, a fault is found in PTC register test the test result passed by touch library fails double inversion check The bit 4 is set if, a fault is found in the input configuration data integrity the CRC value computed by touch library fails double inversion check The bit 5 is set if at least one touch pin is not connected with the sensor electrode. The bit 6 is set if, the sf_selfcap_fmea_test() function is called before executing the initialization function if the channel number passed to sf_selfcap_fmea_test_open_pins_per_channel() function is greater than DEF_SELFCAP_NUM_CHANNELS. The bit 7 is set if, faults_to_report_inv invalid parameters are passed to the FMEA initialization function when the CRC value computed by the touch library for the input configuration data fails the double inverse check the input pointer is NULL. Compliment value of field faults_to_report Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 91 Values Description y_lines_fault_vcc If bit n is set, then Yn pin is short to Vcc y_lines_fault_vss If bit n is set, then Yn pin is short to Vss This array maps FMEA faults to individual channel numbers. This variable is applicable only if SELFCAP_FMEA_MAP_FAULT_TO_CHANNEL macro is defined in sf_fmea_samd_api.h file. This is used to map FMEA faults to individual channel numbers. Each byte in the array corresponds to the FMEA faults in the particular channel number. Example: FMEA_CHANNEL_STATUS[0] represents the fault of the channel number 0. Each bit in the byte represents the FMEA test status. Example: fmea_channel_status [DEF_SELFCAP_NUM_CHANN ELS] Bit 0 represents the short to Vcc. Bit 1 represents the short to Vss. Bit 2 represents the short to PINS. Bit 5 represents the open pin fault. If Y pin corresponding to a channel is shorted to Vcc then the Bit 0 position of that specific byte will be set to 1. If Y pin corresponding to the channel is shorted to Vss then the Bit 1 position of that specific byte will be set to 1. If Y pin corresponding to the channel is shorted to other Y pins, the Bit 2 of all the channel which uses the faulty Y will be set to 1. Bit 5 of all the channels whose sensor electrode is not connected to the device pin is set to 1. Since PTC register test, configuration data integrity, pre-test failure and initialization failure are common for all the channels, fmea_channel_status will not contain those information. Note: The application must validate the field faults_to_report by performing the double inversion check on faults_to_report variable using the faults_to_report_inv variables. 92 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 5.4 Global Variables 5.4.1 sf_xxxxcap_fmea_fault_report_var Type Description sf_xxxxcap_fmea_fault_re port_t 5.5 Functions 5.5.1 sf_xxxxcap_fmea_init Holds the test status from the latest sf_xxxxcap_fmea_test() call. Refer Section 5.3.3 for mutual capacitance and Section 5.3.4 for self capacitance related information. The members, faults_to_report and faults_to_report_inv of sf_xxxxcap_fmea_fault_report_var variable must be verified for double inversion before using any other member of this variable. This function initializes all the FMEA related variables and verifies if the input parameters are within predefined range. If the values are outside the predefined range, the faults_to_report field of sf_xxxxcap_fmea_fault_report_var global structure is updated with an FMEA_ERROR_INIT error. If the values are within the range, the touch library computes the CRC for the input configuration data. The FMEA validates the CRC value passed by the touch library by performing double inverse check. If the double inverse check fails, the FMEA_ERROR_INIT is reported in the variable sf_xxxxcap_fmea_fault_report_var. This function must be called after performing the touch initialization. The application should check the variable sf_xxxxcap_fmea_fault_report_var after calling this function and ensure that the initialization has not failed. void sf_xxxxcap_fmea_init(sf_xxxxcap_fmea_config_t sf_xxxxcap_fmea_input_config) Fields Type Description sf_xxxxcap_fmea_inpu t_config sf_xxxxcap_fmea_input_ config_t The input parameters are passed through this structure Return: None. 5.5.2 sf_xxxxcap_fmea_test This function performs various FMEA tests based on the input parameter and updates the global structure sf_xxxxcap_fmea_fault_report_var which contains the FMEA fault status. Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 93 void sf_xxxxcap_fmea_test(uint16_t select_checks) Fields Type Description Bit masks of the tests that must be performed. select_checks uint16_t If bit 0 is set as 1, Short to Vcc test is performed. If bit 1 is set as 1, Short to Vss test is performed. If bit 2 is set as 1, Short to Pins test is performed. If bit 3 is set as 1, PTC register test is performed. If bit 4 is set as 1, input configuration data integrity test is performed. If any bit is set to 0, the corresponding FMEA test is not performed. Bit 5 to 15 are reserved in this field. The application should not call this function by setting them. Return: None. 94 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 5.5.3 sf_xxxcap_fmea_test_open_pins_per_channel Open pin test is performed by receiving the CC value for the current channel number from touch library. If the CC value received from the touch library is less than or equal to the configured minimum value, then the error counter for that channel is incremented. Error counter will also be incremented if double inverse check of the CC value is failed. If the error counter reaches the configured minimum number of error count, then the FMEA_ERR_OPEN_PINS error is updated in sf_xxxxcap_fmea_fault_report_var and the sample and error counter of that channel is reset to zero. If the sample counter reaches the configured maximum number of channels, then the error counter and sample counter are reset to zero. Figure 5-1. Working Mechanism of the Error and Sample Counter Start Get cc_val from touch lib for ch_num sample_cnt[ch_num]++; err_status = 0; Is (cc_val <= cc_cal_valid_min_val) or cc_val failed double inverse check ? Yes err_cnt[ch_num]++; No Yes Is err_cnt[ch_num] >= N1 err_status = 1; No Yes Is sample_cnt[ch_num] >= N2 err_cnt[ch_num] = 0; sample_cnt[ch_num] = 0; No Update the fmea general status with err_status; End Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 95 This API can be called using one of the three modes. Mode 1: Application Tracking the Next Channel Number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f the channel number passed as parameter is less than DEF_XXXXCAP_NUM_CHANNELS, this function performs open pin test for the specified channel number. In this mode, the application can decide the channel number to be tested during each run. 96 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 Mode 2: FMEA Tracking the Next Channel Number Application FMEA System Power up sf_xxxxcap_fmea_init() FMEA Initialization ch_num_track = 0; Function call return Application working condition sf_xxxxcap_fmea_open_pin_per_channel (DEF_XXXXCAP_NUM_CHANNELS) ch_num = ch_num_track; Function call return Perform open pin test for ch_num ch_num_track++; Is ch_num_track == DEF_XXXXCAP_NUM_CHANNEL S? ch_num_trac k=0 Open Pin test complete callback function(ch_num) Fault Action Yes Fault ? No Function call return sf_xxxxcap_fmea_open_pin_per_channel ch_num = ch_num_track; Function call return Perform open pin test for ch_num ch_num_track++; Is ch_num_track == DEF_XXXXCAP_NUM_CHANNEL S? ch_num_trac k=0 Open Pin test complete callback function(ch_num) Fault Action Yes Fault ? No Function call return The application can let the FMEA to track the channel number by passing DEF_XXXXCAP_NUM_CHANNELS as the input value. For each call to sf_xxxxcap_fmea_open_pins_per_channel with DEF_XXXXCAP_NUM_CHANNELS as the Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 97 input value, open pin test will be performed on one channel (referred as sf_xxxxcap _fmea_open_test_ch_track). At FMEA initialization, sf_xxxxcap_fmea_open_test_ch_track is initialized to 0. After each test, sf_xxxxcap_fmea_open_test_ch_track is incremented by 1. When sf_xxxxcap_fmea_open_test_ch_track reaches DEF_XXXXCAP_NUM_CHANNELS, it is reset to 0. Mode 3: Both FMEA and Application tracking the channel number Application FMEA System Power up sf_xxxxcap_fmea_init() FMEA Initialization ch_num_track = 0; Function call return Application working condition sf_xxxxcap_fmea_open_pin_per_channel (DEF_XXXXCAP_NUM_CHANNELS) ch_num = ch_num_track; Function call return Perform open pin test for ch_num ch_num_track++; Is ch_num_track == DEF_XXXXCAP_NUM_CHANNEL S? ch_num_trac k=0 Open Pin test complete callback function(ch_num) Fault Action Yes Fault ? No Function call return app_ch_num = N; sf_xxxxcap_fmea_open_pin_per_channel(app_ch_num) ch_num = app_ch_num; Function call return Perform open pin test for ch_num Open Pin test complete callback function(ch_num) Fault Action Yes Fault ? No Function call return In mode 3, sf_xxxxcap_fmea_test_open_pins_per_channel() can be called with input parameter value in the range of 0 to DEF_XXXXCAP_NUM_CHANNELS. Whenever the input parameter value is in the range of 0 to DEF_XXXXCAP_NUM_CHANNELS-1, this function performs open pin test for the specified channel number. Whenever the input parameter value is equal to DEF_XXXXCAP_NUM_CHANNELS, open pin test will be performed on one channel number sf_xxxxcap_fmea_open_test_ch_track. sf_xxxxcap_fmea_open_test_ch_track is 98 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 incremented by after performing the test. If the sf_xxxxcap_fmea_open_test_ch_track is equal to or greater than DEF_XXXXCAP_NUM_CHANNELS, then sf_xxxxcap_fmea_open_test_ch_track reset to 0. In all these modes, the application should initiate the next open pin test only after receiving the callback function for the previously initiated open pin test. void sf_xxxxcap_fmea_test_open_pins_per_channel (uint16_t ch_num) If the channel number passed is greater than DEF_XXXXCAP_NUM_CHANNELS, sf_xxxxcap_fmea_fault_report_var is updated with FMEA_ERR_PRE_TEST error. Return: None. then the The sf_xxxxcap_fmea_test_open_pins_per_channel() calls the open pin test complete callback function after performing open pin test for the specified channel. The application should check the open pin test status only after the open pin test complete callback function is called. void sf_xxxxcap_fmea_test_open_pins_per_channel (uint16_t ch_num) Data Fields Arguments Type Description ch_num unint16_t Channel number for which the open pin test must be performed Return: None. The sf_xxxxcap_fmea_test_open_pins_per_channel() calls the open pin test complete callback function after performing open pin test for the specified channels. The application should check the open pin test status only after the open pin test complete callback function is being called for the respective touch acquisition technology. Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 99 5.5.4 sf_xxxxcap_fmea_stop Application FMEA System Power up sf_xxxxcap_fmea_init() FMEA Initialization Function call return Application working condition sf_xxxxcap_fmea_test() Perform FMEA Test Function call return Fault Action Yes Fault ? No Application working condition sf_xxxxcap_fmea_stop() Function call return sf_xxxxcap_fmea_init() FMEA Initialization Function call return sf_xxxxcap_fmea_test() Perform FMEA Test Function call return Fault Action Yes Fault ? No This function stops the FMEA component operation and change the FMEA init status to uninitialized state. The global variables used by the FMEA are reset to default value. The application cannot execute further FMEA tests without reinitializing the FMEA component. void sf_xxxxcap_fmea_stop (void) Arguments Type Description None None None Return: None. 100 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 5.6 Macros DEF_TOUCH_FMEA_MUTLCAP_ENABLE and DEF_TOUCH_FMEA_SELFCAP_ENABLE must be set to 1 to enable mutual cap and self cap FMEA respectively. Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 101 6. System 6.1 Relocating Touch Library and FMEA RAM Area The data corresponding to the touch library and FMEA are placed at specific sections in the RAM. This is done so that the customer application can perform the static memory analysis test on the touch and FMEA RAM area as per the Class B safety requirements. To create these two RAM sections (Touch and FMEA), the linker file must be modified as per the description in the following sections. Notes: 1. All the variables related to touch sensing (filter callback, touch input configuration, gain variables and others) in touch.c application file must be re-located to touch library RAM section. 2. Following warning may be displayed in IAR IDE: Warning[Be006]: possible conflict for segment/section. This warning is thrown due to relocation of configuration variables in touch.c and FMEA variables which contains both initialized and zero initialized data to the TOUCH_SAFETY_DATA_LOCATION and TOUCH_FMEA_DATA_LOCATION sections, respectively. This warning will not affect the safe operation of the system. This warning can be safely discarded or if required the same can be suppressed using diagnostic tab in IAR project options. 6.1.1 Modifying the IAR Linker File Touch Library RAM Section The changes should be done in <devicevariant>_flash.icf file as follows: Linker symbols should be added in linker file to denote the start and size of the touch library RAM section. The size of touch RAM section (SIZE_OF_TOUCH_SAFETY_DATA_LOCATION) should be calculated as per Section 2.10. Table 6-1. IAR Linker Symbols for Touch RAM Data Symbol in Linker File Description TOUCH_SAFETY_DATA_LOCATION_region Touch Library Data Memory Region to be created in linker file. TOUCH_SAFETY_DATA_LOCATION Touch library Data Section to be created in linker file SIZE_OF_TOUCH_SAFETY_DATA_LOCATION Size of Touch Library RAM data TOUCH_SAFETY_DATA_LOCATION_START The absolute address of RAM from where touch library RAM variables would be placed in TOUCH_SAFETY_DATA_LOCATION section TOUCH_SAFETY_DATA_LOCATION_END End location of the TOUCH_SAFETY_DATA_LOCATION section An example setting is as follows: define symbol TOUCH_SAFETY_DATA_LOCATION_START = 0x20004000; define symbol SIZE_OF_TOUCH_SAFETY_DATA_LOCATION = 0x05DC; define symbol TOUCH_SAFETY_DATA_LOCATION_END = (TOUCH_SAFETY_DATA_LOCATION_START + SIZE_OF_TOUCH_SAFETY_DATA_LOCATION -1); 102 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 FMEA RAM Section Linker symbols should be added in linker file to denote the start and size of the FMEA library RAM section. The size of FMEA RAM section (SIZE_OF_FMEA_SAFETY_DATA_LOCATION) should be calculated as per section Section 4.2. Table 6-2. IAR Linker Symbols for FMEA RAM Data Symbol in Linker File Description FMEA_SAFETY_DATA_LOCATION_region FMEA Library Data Memory Region to be created in linker file FMEA_SAFETY_DATA_LOCATION FMEA library Data Section to be created in linker file SIZE_OF_FMEA_SAFETY_DATA_LOCATION Size of FMEA Library RAM data FMEA_SAFETY_DATA_LOCATION_START The absolute address of RAM from where FMEA library RAM variables would be placed in FMEA_SAFETY_DATA_LOCATION section FMEA_SAFETY_DATA_LOCATION_END End location of the FMEA_SAFETY_DATA_LOCATION section An example setting is as follows: define symbol FMEA_SAFETY_DATA_LOCATION_START = 0x20004000; define symbol SIZE_OF_FMEA_SAFETY_DATA_LOCATION = 0x05DC; define symbol FMEA_SAFETY_DATA_LOCATION_END = (FMEA_SAFETY_DATA_LOCATION_START + SIZE_OF_FMEA_SAFETY_DATA_LOCATION -1); Note: More information can be found at page 85, Linking Your Application in [3]. Refer [4] for the version of IAR toolchain used. 6.1.2 Modifying GCC Linker File The changes should be done in <devicevariant>_flash.ld file as follows: Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 103 Touch Library RAM Section Symbol in Linker File Description TOUCH_SAFETY_DATA_LOCATION_region Touch Library Data Memory Region to be created in linker file. The ORIGIN field in the memory region should be the starting address of the touch library RAM data and LENGTH field should be the size of the touch library RAM data. TOUCH_SAFETY_DATA_LOCATION Touch library Data Section to be created in linker file SIZE_OF_TOUCH_SAFETY_DATA_LOCATION Size of Touch Library RAM data TOUCH_SAFETY_DATA_LOCATION_START The absolute address of RAM from where Touch library RAM variables would be placed in TOUCH_SAFETY_DATA_LOCATION section TOUCH_SAFETY_DATA_LOCATION_END End location of the TOUCH_SAFETY_DATA_LOCATION section _sTOUCH_SAFETY_DATA_LOCATION It holds the start address of the TOUCH_SAFETY_DATA_LOCATION in FLASH _eTOUCH_SAFETY_DATA_LOCATION It holds the end address of the TOUCH_SAFETY_DATA_LOCATION in FLASH The TOUCH_SAFETY_DATA_LOCATION_START, _sTOUCH_SAFETY_DATA_LOCATION, TOUCH_SAFETY_DATA_LOCATION_END and _eTOUCH_SAFETY_DATA_LOCATION variables would be used in the startup_samd20.c or startup_samd21.c file to initialize the Touch library RAM section from FLASH. 104 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 FMEA Library RAM Section Symbol in Linker File Description FMEA_SAFETY_DATA_LOCATION_region FMEA Library Data Memory Region to be created in linker file. The ORIGIN field in the memory region should be the starting address of the FMEA library RAM data and LENGTH field should be the size of the FMEA library RAM data. FMEA_SAFETY_DATA_LOCATION FMEA library Data Section to be created in linker file SIZE_OF_FMEA_SAFETY_DATA_LOCATION Size of FMEA Library RAM data FMEA_SAFETY_DATA_LOCATION_START The absolute address of RAM from where FMEA library RAM variables would be placed in TOUCH_SAFETY_DATA_LOCATION section FMEA_SAFETY_DATA_LOCATION_END End location of the FMEA_SAFETY_DATA_LOCATION section _sFMEA_SAFETY_DATA_LOCATION It holds the start address of the FMEA_SAFETY_DATA_LOCATION in FLASH _eFMEA_SAFETY_DATA_LOCATION It holds the end address of the FMEA_SAFETY_DATA_LOCATION in FLASH The FMEA_SAFETY_DATA_LOCATION_START, _sFMEA_SAFETY_DATA_LOCATION, FMEA_SAFETY_DATA_ LOCATION_END and _eFMEA_SAFETY_DATA_LOCATION variables would be used in the startup_samd20.cor startup_samd21.c file to initialize the FMEA library RAM section from FLASH. Note: More information can be found on linker script at page 37 in [6]. 6.2 API Rules All safety APIs must be incorporated in to a system as per the following rules: a. Both FMEA and Touch library must be initialized at least once after power-up. FMEA can be initialized again after stopping the FMEA. b. The periodicity for calling safety test APIs is controlled by the application. c. Few safety test APIs will lock interrupts during the test period since interrupts could potentially disrupt the safety functionality. Refer Section 2.11 for information about Touch Library. FMEA component is functionally dependent on Atmel touch library. Hence FMEA test must be performed only after the touch library is initialized. Touch library is a pre-requisite for FMEA firmware, Include the FMEA firmware, only when the Touch library is included in the system. Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 105 6.3 Safety Firmware Action Upon Fault Detection On detection of a fault within an IEC safety test API, the safety firmware can perform the corrective action. A. Touch library action upon fault detection. B. FMEA library action upon fault detection. If a fault is detected by the FMEA library, it will update the fault in the global structure sf_xxxxcap_fmea_fault_report_var. 6.4 System Action Upon Fault Detection The fault action routine must be designed by the user and will be system dependent. The following options can be considered for the fault actions routines: a) Application may inform the host about the failure, provided the failure does not impact the communication with the host controller. b) Lock the system by disabling interrupt. Perform other possible clean-up actions and lock the system. c) The system can clean-up and shutdown other safety systems and reset the system. 6.5 Touch Library and FMEA Synchronization The following entities are mutually exclusive and cannot be executing an activity (touch measurement or FMEA test) simultaneously. Self-cap touch library Mutual-cap touch library Self-cap FMEA Mutual-cap FMEA The customer application should establish a synchronization mechanism to manage the exclusivity of the entities. The following tables provides the information about the FMEA APIs, Touch library APIs and their corresponding action to indicate completion. Table 6-3. FMEA API Execution Completion Indicators API Name Completion Indication sf_xxxxcap_fmea_init Function call return sf_xxxxcap_fmea_test Function call return sf_xxxxcap_fmea_test_o pen_pin_per_channel Open pin test complete callback function call sf_xxxxcap_fmea_stop Function call return 106 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 Table 6-4. API Execution Completion Indicators API Completion Indication touch_xxxxcap_sensors_init Function call return touch_xxxxcap_di_init Function call return touch_xxxxcap_sensor_config Function call return touch_xxxxcap_sensors_calibrate Measure complete callback function call touch_xxxxcap_calibrate_single_sensor Measure complete callback function call touch_xxxxcap_sensors_measure Measure complete callback function call with Application burst again set to zero touch_xxxxcap_sensor_get_delta Function call return touch_xxxxcap_sensor_update_config Function call return touch_xxxxcap_sensor_get_config Function call return touch_xxxxcap_sensor_update_acq_config Function call return touch_xxxxcap_sensor_get_acq_config Function call return touch_xxxxcap_update_global_param Function call return touch_xxxxcap_get_global_param Function call return touch_xxxxcap_get_libinfo Function call return touch_lib_pc_test_magic_no_1 Function call return touch_lib_pc_test_magic_no_2 Function call return touch_lib_pc_test_magic_no_3 Function call return touch_lib_pc_test_magic_no_4 Function call return touch_xxxxcap_sensor_disable Function call return touch_xxxxcap_sensor_reenable Function call return touch_library_get_version_info Function call return touch_xxxxcap_cnfg_mois_mltchgrp Function call return touch_xxxxcap_cnfg_mois_threshold Function call return touch_xxxxcap_mois_tolrnce_enable Function call return touch_xxxxcap_mois_tolrnce_disable Function call return touch_calc_xxxxcap_config_data_integrity Function call return touch_test_xxxxcap_config_data_integrity Function call return Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 107 6.6 Safety Firmware Package The following files corresponding to the safety component. Safety Component Files sf_mutlcap_fmea_samd.c sf_selfcap_fmea_samd.c FMEA touch_fmea_api_samd.h sf_fmea_samd_api.h sf_fmea_samd_int.h libsamd20_safety_iar.a libsamd20_safety_gcc.a Touch Library libsamd21_safety_iar.a libsamd21_safety_gcc.a touch_safety_api_samd.h 6.7 SAMDSafety Firmware Certification Scope The Class-B IEC certification of the following modules are supported and compiled by FMEA and Safety Touch Library. The following activities must be performed by the user to achieve IEC certification for the overall system: Risk analysis for the system IEC certification for the critical and supervisory sections of the system 6.8 Hazard Time It is the responsibility of the application to ensure that the optimal configuration is selected for the individual test components (FMEA) to achieve the hazard time requirement of the end user system as per the [1] and [2]. Note: The hazard time for various types of failure is not defined by Atmel. It is based on the test configuration and periodicity selected by the user designing the end user system or application. 6.9 ASF Dependency The Atmel® Software Framework (ASF) is a MCU software library providing a large collection of embedded software for different Atmel MCUs. It simplifies the usage of microcontrollers, providing an abstraction to the hardware and highvalue middle wares. The Touch Library and FMEA is dependent on the ASF. ASF is available as standalone package for IAR compilers and can be downloaded from Atmel website. For more information and an overview about ASF visit: http://www.atmel.com/tools/ AVRSOFTWAREFRAMEWORK.aspx. The latest ASF standalone package is available for download in the download page in the Software Category in www.atmel.com. 6.10 Robustness and Tuning Please refer AT08578: SAM D20 QTouch Robustness Demo User Guide and AT09363: PTC Robustness Design Guide. 6.11 Standards compliance Atmel Safety Library is compliant with the following list of IEC, EN and UL standards. UL Compliance UL 60730-1, IEC 60730-1 and CSA E60730-1, Automatic electrical controls UL 60335-1 and IEC 60335-1, Household and similar electrical appliances UL 60730-2-11 and IEC 60730-2-11, Energy Regulators UL 1017 and IEC 60335-2-2, Vacuum Cleaners and Water-Suction Cleaning Appliances UL 749, UL 921, and IEC 60335-2-5, Dishwashers UL 858 and IEC 60335-2-6, Stationary Cooking Ranges, Hobs, Ovens, and Similar Appliances UL 1206, UL 2157, and IEC 60335-2-7, Washing Machines UL 1240, UL 2158, and IEC 60335-2-11, Tumble Dryers UL 1083 and IEC 60335-2-13, Deep Fat Fryers, Frying Pans, and Similar Appliances UL 982 and IEC 60335-2-14, Kitchen Machines UL 1082 and IEC 60335-2-15, Appliances for Heating Liquids UL 923 and IEC 60335-2-25, Microwave Ovens, Including Combination Microwave Ovens UL 197 and IEC 60335-2-36, Commercial Electric Cooking Ranges, Ovens, Hobs, and Hob Elements UL 197 and IEC 60335-2-37, Commercial Electric Doughnut Fryers and Deep Fat Fryers UL 73, UL 499, and IEC 60335-2-54, Surface-Cleaning Appliances for Household Use Employing Liquids or Steam UL 499, UL 1776, and IEC 60335-2-79, High Pressure Cleaners and Steam Cleaners UL 507 and IEC 60335-2-80, Fans Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 109 VDE Compliance IEC/EN 60730-1, Automatic electrical controls IEC/EN 60335-2-11, Energy regulators IEC/EN 60335-1, Safety of household appliances IEC/EN 60335-2-5, Dishwashers IEC/EN 60335-2-6, Hobs, ovens and cooking ranges IEC/EN 60335-2-7, Washing machines IEC/EN 60335-2-9, Grills, toasters and similar portable cooking appliances IEC/EN 60335-2-14 Kitchen machines IEC/EN 60335-2-15,Heating liquids IEC 60335-2-25 Microwave ovens including combination micro wave ovens IEC 60335-2-33 Coffeemills and coffee IEC 60335-2-36 Commercial electric cooking ranges, ovens, hobs and hob elements IEC 60730-2-11 Energy regulators 6.12 Safety Certification A Safety Certification "mark" on a product indicates that it has been tested against the applicable safety in a certain region and found to be in compliance. A National Certification Body (NCB) is an organization that grants nationally recognized conformity certificates and marks to products such asVDE and UL are NCBs in Germany and USA, respectively. The IECEE CB Scheme is an international system for mutual acceptance of test reports and certificates dealing with the safety of electrical and electronic components, equipment and products. The tests performed by one national NCB and the resulting CB-certificates / test reports are the basis for obtaining the national certification of other participating NCBs, subject to any National Differences being met. The following diagram illustrates the typical CB scheme flow. 110 Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 7. References For more information and knowledge about the safety component for SAM devices, refer the following: [1]: IEC 60730-1: IEC60730-1 Standard for Safety for Software in Programmable Components [2]: SAMD20 device data sheet (http://www.atmel.com/Images/Atmel-42129-SAM-D20_Datasheet.pdf) [3]: IAR C/C++ Compiler Guide (http://supp.iar.com/FilesPublic/UPDINFO/004916/ arm/doc/EWARM_DevelopmentGuide.ENU.pdf) [4]: IAR Embedded Workbench for ARM – Version 7.40 [5]: Buttons, Sliders and Wheels Touch Sensor Design Guide (http://www.atmel.com/Images/doc10752.pdf) [6]: GCC Linker pdf (https://sourceware.org/binutils/docs/ld/) [7]: SAMD21 device data sheet (http://www.atmel.com/Images/Atmel-42181-SAM-D21_Datasheet.pdf) Atmel | SMART SAM QTouch Safety Library [User Guide] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 111 8. Revision History Doc. Rev. Date F 10/2015 Minor non-technical updates E 09/2015 Added AutoOversample, Filter level, PTC Resistor selection and PTC Prescaler on a per channel basis, and Touch De-init APIs D 05/2015 Included Suspend and Resume PTC Operation Feature C 11/2014 Enhanced release with Noise Immunity and Moisture Control Features B 04/2014 Enhanced release with Noise Immunity Features A 01/2014 Initial document release 112 Comments Atmel | SMART SAM QTouch Safety Library [USER GUIDE] Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-UserGuide_10/2015 XXXXXX Atmel Corporation 1600 Technology Drive, San Jose, CA 95110 USA T: (+1)(408) 441.0311 F: (+1)(408) 436.4200 | www.atmel.com © 2015 Atmel Corporation. / Rev.: Atmel-42230F-SAM-Atmel SAMD QTouch Safety Library-Datasheet_10/2015. Atmel®, Atmel logo, Enabling Unlimited Possibilities®, and combinations thereof, and others are registered trademarks or trademarks of Atmel Corporation or its subsidiaries. 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