RN -17 1-DS RN-171 802.11 b/g Wireless LAN Module Features • FCC/CE/IC certified 2.4-GHz IEEE 802.11b/g transceiver • Small form factor: 1050 x 700 x 130 mil • Configurable transmit power: 0 to 10 dBm • RF pad connector for antennas • Certified antennas: chip antenna, 4” dipole, PCB trace, and wire antenna • Ultra-low power: 4-uA sleep, 38-mA Rx, 120-mA Tx at 0 dBm • High throughput: 921 Kbps TX, 500 Kbps RX data rate with TCP/IP and WPA2 over UART, up to 2 Mbps over SPI slave • 8-Mbit flash memory and 128-KB RAM • 10 general-purpose digital I/O pins • 8 analog sensor interfaces • Real-time clock for wakeup and time stamping • Accepts 3.3-V regulated power supply or 3-V battery • Supports ad hoc and infrastructure networks • Complete on-board TCP/IP networking stack • Environmentally friendly: RoHS compliant Remote equipment monitoring • Telemetry • Industrial sensors and home automation controls • Home automation The RN-171 module is a complete, standalone TCP/IP wireless networking module. With its small form factor and extremely low power consumption, the RN-171 is perfect for mobile wireless applications such as asset monitoring, sensors, and portable battery operated devices. It incorporates a 2.4-GHz radio, 32-bit SPARC processor, TCP/IP stack, real-time clock, crypto accelerator, power management, and analog sensor interfaces. The module is preloaded with firmware to simplify integration and minimize application development. In the simplest configuration, the hardware only requires four connections (PWR, TX, RX, and GND) to create a wireless data connection. Additionally, the analog sensor inputs can connect to a variety of sensors such as temperature, audio, motion, and acceleration. The ability to go into deep sleep mode and automatically scan and associate to an access point when awake makes the RN-171 suitable for roaming applications. The RN-171 also includes a built-in HTML client to post serial UART data or sensor data to a web server automatically. Applications • Description Figure 1. RN-171 Block Diagram RN-171 Trace for PCB Antenna 2.4 GHz TX/RX 128-KB RAM 2.4-GHz PA 802.11 b/g MAC/PHY Crypto accelerator Sensor Interface ADC 2-MB ROM 2-KB NVM 2.4-GHz Radio 32-Bit CPU Pwr Mgmt Flash Memory Timers SPI GPIO SPI GPIO UART VDD IN VDD BATT SDIO www.rovingnetworks.com Version 3.21 10/2/2012 1 RN -17 1 OVERVIEW • Host data rates up to 921 Kbps TX, 500 Kbps RX for the UART, up to 2 Mbps over the SPI slave • Intelligent, built-in power management with programmable wakeup • Real-time clock for time stamping, auto-sleep, and auto-wakeup • Configuration using simple ASCII commands • Software controlled transmit power (0 to 10 dBm) for ultra-low-power applications • Memory: 128-KB RAM, 2-MB ROM, 2-KB battery-backed memory, 8-Mbit flash • Secure Wi-Fi authentication using WEP-128, WPA-PSK (TKIP), and WPA2-PSK (AES) • Built-in networking applications: DHCP, UDP, DNS, ARP, ICMP, TCP, and HTML client • 802.11 power save and roaming functions • Castellated pads for reliable soldering The module’s moisture sensitivity level (MSL) is 1. The modules size and weight are: • Size—1.06 x 0.70 x 0.12 inches (27 x 18 x 3.1 mm) • Weight—0.09 oz Tables 1 through 5 provide detailed specifications for the module. Table 1. Environmental Conditions Parameter RN-171 o o o o Temperature Range (Operating) -40 C ~ +85 C Temperature Range (Storage) -40 C ~ +85 C Relative Humidity (Operating) ≤90% Relative Humidity (Storage) ≤90% Table 2. Electrical Characteristics (Provisional) Supply Voltage Supply voltage (VBATT option) Min. Typ. Max. Units 3.0 3.3 3.7 VDC Digital input Input logic high VIH 2.3 VDC Input logic low VIL 1.0 VDC Digital Output Drive GPIO 4, 5, 6, 7, 8 24 mA GPIO 9, 10, 11, 12, 13 8 mA Power Consumption Sleep 4 Standby (doze) - Connected (idle, RX) Connected (TX)* 15 uA - mA 40 mA 0 dBm 120 mA 12 dBm 190 mA www.rovingnetworks.com Version 3.21 10/2/2012 2 RN -17 1 Table 3. Analog Sensor Inputs Parameter Value Sensor 0, 1, 2, 3 wakeup detection threshold 500 mV AD sensor 0 - 7 measurement range 0 - 400 mV (Do not exceed 1.2-V DC) Resolution 14 bits = 12uV Accuracy 5% un-calibrated, .01% calibrated Minimum conversion time 35 us (5 kHz over Wi-Fi) Sensor power (pin 33) output resistance 3.3V 10 ohms, maximum current = 50 mA Table 4. Radio Characteristics Parameter Specifications Frequency 2,402 ~ 2,480 MHz Modulation 802.11b compatibility: DSSS (CCK-11, CCK-5.5, DQPSK-2, DBPSK-1) 802.11g: OFDM (default) Channel intervals 5 MHz Channels 1 – 14 Transmission rate (over the air) 1 – 11 Mbps for 802.11b / 6 – 54 Mbps for 802.11g Receive sensitivity -83 dBm typical Output level (class1) -2 dBm to +12 dBm (configurable via software) Table 5. Transmit Power Output Power 802.11 b (2 Mbps) Current in mA Note (1) 802.11 g (24 Mbps) Current in mA Note (1) 0 120 135 2 130 150 4 170 190 6 175 200 8 180 210 10 185 225 12 190 240 Note: 1. Measured at 3.3-V DC VCC. The power consumption is the average power, active during actual power consumption. www.rovingnetworks.com Version 3.21 10/2/2012 3 RN -17 1 TYPICAL APPLICATION SCHEMATIC Figure 2 shows a typical application schematic with a battery boost circuit; Figure 3 shows a typical schematic with a linear regulator. Figure 2. Application Schematic with Battery Boost Circuit www.rovingnetworks.com Version 3.21 10/2/2012 4 RN -17 1 Figure 3. Typical Application Circuit with Linear Regulator Figure 4 shows the pin pads and Table 6 describes the pins. Figure 4. Pin Pads 19 20 17 18 15 16 13 14 11 12 9 10 7 8 5 3 6 4 1 2 48 21 22 23 24 25 26 27 49 Top View 29 28 31 30 35 33 32 34 37 36 39 38 41 40 43 42 44 45 47 46 www.rovingnetworks.com Version 3.21 10/2/2012 5 RN -17 1 Table 6. Pin Description Pad Number Signal Name Description Optional Function Direction Note (1) 1 GND Ground. - 2 Unused Do not connect. No Connect 3 Unused Do not connect. No Connect 4 GPIO9 Enable ad hoc mode, restore factory defaults, 8 mA drive, 3.3-V tolerant. I/O 5 GPIO8 GPIO, 24-mA drive, 3.3-V tolerant. The RN-171 drives GPIO8 HIGH on powerup, which overrides software configured powerup values, such as set sys value 0x0000 on GPIO8. I/O 6 GPIO7 GPIO, 24-mA drive, 3.3-V tolerant. 7 GPIO6 GPIO, 24-mA drive, 3.3-V tolerant, connection status on Roving Networks’ firmware. Status of access point association I/O 8 GPIO5 GPIO, 24-mA drive, 3.3-V tolerant. Data Tx/Rx status I/O 9 GPIO4 GPIO, 24-mA drive, 3.3-V tolerant. Connected over TCP status I/O 10 VDD_3.3V 3.3-V power supply. 11 GPIO3 GPIO, 8-mA drive, 3.3-V tolerant. I/O 12 GPIO2 GPIO, 8-mA drive, 3.3-V tolerant. I/O 13 GPIO1 GPIO, 8-mA drive, 3.3-V tolerant. I/O 14 GND Ground. - 15 Unused Do not connect. No Connect 16 Unused Do not connect. No Connect 17 Unused Do not connect. No Connect 18 Unused Do not connect. No Connect 19 Unused Do not connect. No Connect 20 GND Ground. - 21, 22, 23 GND Ground. - 24 ANTENNA 802.11b/g 2.4-Ghz antenna. - 25, 26, 27 GND Ground. - 28 GND Ground. - 29 SENSOR 0 (2), (3) Sensor interface, analog input to module, 1.2-V tolerant. Input 30 SENSOR 1 (2), (3) Sensor interface, analog input to module, 1.2-V tolerant. Input 31 SENSOR 2 (2), (3) Sensor interface, analog input to module, 1.2-V tolerant. Input 32 SENSOR 3 (2), (3) Sensor interface, analog input to module, 1.2-V tolerant. Input 33 SENSOR POWER Output voltage from module, 3.3 V max. - 34 VDD_3.3V_RF 3.3-V RF power supply (connect to 3.3-V rail). - 35 SENSOR 4 (3) Sensor interface, analog input to module, 1.2-V tolerant. Input 36 SENSOR 5 (3) Sensor interface, analog input to module, 1.2-V tolerant. Input 37 SENSOR 6 (3) Sensor interface, analog input to module, 1.2-V tolerant. Input 38 SENSOR 7 (3) Sensor interface, analog input to module, 1.2-V tolerant. Input 39 GND Ground. - 40 RESET Optional module reset signal (active low), 100-k pull up, apply pulse of at least 160 us, 3.3-V tolerant. Input 41 FORCE_AWAKE Optional module awake signal (active high), 100-k pull down, apply pulse of at least 260 us, 3.3-V tolerant. Input 42 GPIO 14 GPIO, 8 mA drive, 3.3-V tolerant. I/O www.rovingnetworks.com Version 3.21 10/2/2012 I/O 6 RN -17 1 Pad Number Signal Name Optional Function Description Direction Note (1) 43 UART_RTS UART RTS flow control, 8-mA drive, 3.3-V tolerant. Output 44 UART_CTS UART CTS flow control, 3.3-V tolerant. Input 45 UART_RX UART RX, 3.3-V tolerant. Input 46 UART_TX UART TX, 8-mA drive, 3.3-V tolerant. Output 47 GND Ground. - 48 SREG_3V3_CTRL Boost regulator control. Output 49 VDD-BATT Battery input, 2.0 - 3.3 V with boost regulator in use, connect to VDD if not using boost regulator. - Notes: 1. Signals marked as input are inputs to the RN-171 module. Signals marked as output are outputs from the module. 2. Any of the sensors 0 - 3 can be used to wake the module. The sensor pins are 1.2-V tolerant. DO NOT apply 3.3-V on these pins. DO NOT apply 3.3-V on any of sensor pins. 3. When sensor pins are used as sensor inputs, they saturate at 400 mV. Sensor pins will accept input voltages up to 1.2 V but will saturate at 400 mV. DO NOT apply 3.3 V on any of sensor pins. Figure 5 shows the module’s physical dimensions. Figure 5. Module Physical Dimensions 1 mil = 0.0254 millimeters 35 mil 50 mil 35 mil 135 mil 185 mil 150 mil 700 mil 185 mil Pad Dimensions: 40 x 90 mil (rounded ends) 1,050 mil www.rovingnetworks.com Version 3.21 10/2/2012 7 RN -17 1 DESIGN CONCERNS The following sections provide information on designing with the RN-171 module, including antenna design, solder reflow, boost regulator, etc. Antenna Design The RN-171 supports several antenna designs, including a PCB trace antenna, chip antenna, wire antenna, and U.FL connector. PCB Trace Antenna Figure 6 shows Roving Networks’ recommended PCB trace antenna pattern. The antenna ground should be connected to the ground plane and/or ground polygon on both the top and bottom layers with at least 2 vias. The ground plane should come close to the antenna, exactly as shown in Figure 6; the distance is critical. There should be no ground place/trace under the antenna under any circumstances. The antenna feed goes through the polygon on a 50-ohm impedance trace to the source of the signal. Unless the antenna trace is exactly 50 ohms and the source has a 50-ohm output impedance, you should use a matching PI filter (2 capacitors and an inductor). The left side of the antenna should be placed on the PCB edge. If that is not possible, leave at least 1 inch of clearance from any trace or ground plane. The top and bottom of the antenna (the shorter side) should be placed on the PCB edge or should have at least 1-inch clearance from any trace or ground plane. To control the impedance of the antenna feed the board should be 4 layers with a dedicated ground plane and a thickness of around 8 - 14 mils between the ground plane and the top layer (where the antenna feed is routed). A 2-layer board would not be thin enough to obtain the desired impedance using an acceptable trace width. Figure 6. PCB Trace Antenna Pattern Antenna Feed Antenna Ground www.rovingnetworks.com Version 3.21 10/2/2012 8 RN -17 1 The trace from the RF pad to the antenna feed should be 12 mils thick on a 4-layer PCB to achieve 50 ohms of impedance matching as shown in Figure 7. Figure 7. Trace from RF Pad to Antenna Feed 12-mil Thick Trace from RF Pad to Antenna Feed Chip Antenna If your design uses a chip antenna, Roving Networks recommends the 2450AT42A100 manufactured by Johanson. Refer to the antenna’s data sheet for additional information such as dimensions, mounting considerations, and radiation patterns. Figure 8 shows the antenna dimensions. www.rovingnetworks.com Version 3.21 10/2/2012 9 RN -17 1 Figure 8. 450AT42A100 Chip Antenna Dimensions Inches mm L 0.197 ± 0.0008 5.00 ± 0.20 W 0.079 ± 0.0008 2.00 ± 0.20 T 0.043 ± 0.0008 1.10 ± 0.20 a 0.020 ± 0.0012 0.50 ± 0.30 W T a L Terminal Configuration No. Function 1 Feeding Point 2 No Connect 2 1 Figure 9 shows the chip antenna’s mounting considerations. Figure 9. Chip Antenna Mounting Considerations 1.0 8.9 3.9 Line width should be designed to provide 50-ohm impedence matching characteristics. 1.8 1.0 4.0 Units: mm Mount these devices with the brown mark facing up. Figure 10 shows the recommended chip antenna layout. Figure 10. Recommended Chip Antenna Layout www.rovingnetworks.com Version 3.21 10/2/2012 10 RN -17 1 The feed connecting the antenna to the RF pad must be 50 ohm in impedance. If this feed is shorter than 0.2" the board can be 2 layers and the thickness of the feed is the same as described in the manufacturer’s data sheet. If the trace is longer, you need a 4-layer board with controlled impedance, i.e., a ground plane directly under the top layer. The thickness should be calculated accordingly. Wire Antenna To implement a wire antenna, drill a hole through the board on the RF pad (pin 24) to place the wire antenna. To provide 50 ohms of impedance matching, the RF path from the RF pad (Pin 24) to the location of the wire antenna should be 12 mils thick on a 4-layer PCB. See Figure 11. Roving Networks recommends that you use an 18-gauge wire with a length of 1 inch ± 0.25. For best performance, the wire antenna should be perpendicular to the ground plane. NOTE: There should be no thermal relief connectors on GND for RF path and on the ground plane. Figure 11. Wire Antenna Location 19 20 A1 17 18 16 21 22 23 24 25 26 27 29 28 31 30 32 U.FL Connector Figure 12 shows one option for implementing a U.FL connector. The trace from the RF pad to the U.FL connector should be 12 mils thick to achieve 50 ohms of impedance matching on a 4-layer board. The part number of the U.FL connector used for certification of the module is U.FL-R-SM from Hirose. www.rovingnetworks.com Version 3.21 10/2/2012 11 RN -17 1 Figure 12. U.FL Connector 19 20 17 18 16 21 22 23 24 25 26 27 29 28 31 30 32 Using Batteries The RN-171 module does not have a boost regulator circuit. The battery choice is absolutely critical because if the battery voltage drops below 3 V, the module performance starts to degrade. One possible battery of choice is the 3.6-V ER14505 battery, which has a long battery life. If this battery is used to power the module, Roving Networks recommends that you use a 1,000 – 3,000 uF bypass capacitor because the ER14505 battery has high output impedance. Boost Regulator The RN-171 does not have an on-board boost regulator. Figure 13 shows a recommended circuit for the boost regulator. Designs that include the boost regulator will provide good power supply to the flash memory even when the battery voltage drops close to 1.8 V. If a board containing the RN-171 does not include a boost regulator, it SHOULD include a 2.7-V under-voltage reset circuit to prevent the module from accessing the flash memory when the supply voltage falls below 2.7 V. All supported flash chips are rated for a minimum VDD of 2.7 V. www.rovingnetworks.com Version 3.21 10/2/2012 12 RN -17 1 Figure 13. Boost Regulator Circuit Table 7 shows the recommended components for the boost regulator circuit. Table 7. Boost Regulator Circuit Components Designator Description D Diode Schottky 1A 20V SMA Inductor 1.0uH 30% SMD MOSFET N-CH 20V 5.9 A L Q Value Manufacturer SS12 Micro Commercial Co Manufacturer Part Number SS12-TP Vendor DigiKey Vendor Part Number SS12-TPCT-ND 1uH Taiyo Yuden NR3015T1R0N DigiKey 587-1647-1-ND DMN2050L Diodes Inc. DMN2050L-7 DigiKey DMN2050LDICT-ND Roving Networks recommends that you use a low voltage detector circuit, such as the XC61 from Torex, tied to the RN-171 module’s RESET pin to protect from low voltage. Powering from a 3.3-V Regulated Source Apply 3.3 V regulated power to pins 10, 34, and 49. Leave pin 48 (SREG_3V3_CTRL) unconnected. NOTE: Do not connect pin 48 to ground. Leave it unconnected. Solder Reflow The reflow temperature must not exceed 220° C. To reflow solder the RN-171 module onto a PCB, Roving Networks recommends a RoHS compliant solder paste equivalent to the NIHON ALMIT paste or OMNIX OM-310 solder paste from Alpha metals. The module pads must have a solder past thickness of 5 mil. NOTE: Use no clean flux. Do NOT water wash! The temperature profile is based on the IC level and other components level only (without the shield can). From the perspective of the module only, a profile above 245° C should be acceptable. See Figures 14 and 15. www.rovingnetworks.com Version 3.21 10/2/2012 13 RN -17 1 Figure 14. Solder Reflow Temperature Profile Figure 15. Solder Reflow Curve www.rovingnetworks.com Version 3.21 10/2/2012 14 RN -17 1 COMPLIANCE INFORMATION Table 8 describes the module’s compliance information. Table 8. Compliance Information Specification Compliance FCC Part 15.247 FCC T9J-RN171 IC RSS-210 low-power communication device CE ID # 0681 REG U9M21103-4249-C RADIO EN 300328 V1.7.1 (10/2006) EMC EN 301489-1 V1.8.1 (04/2008) EN 301489-17 V2.1.1 (05/2009) SAFETY EN 60950-1:2006+A11:2010 EN 50371 2002-03 RoHs Compliant ORDERING INFORMATION Table 9 provides ordering information. Table 9. Ordering Information Part Number Description RN-171 Industrial Temperature (- 40 to + 85 C) with RF pad for external antenna. RN-174 Development board for RN-171 module containing an RS-232 and TTL UART hardware interface, status LEDs, power regulator, and sensor connections. RN-SMA4-RP 4” external antenna with reverse polarity SMA connector. Used with RN-UFL-SMA6. RN-UFL-SMA6 6” cable with U.FL connector on one end and SMA on the other. For other configurations, contact Roving Networks directly. Go to http://www.rovingnetworks.com for current pricing and a list of distributors carrying Roving Networks products. www.rovingnetworks.com Version 3.21 10/2/2012 15 RN -17 1 Copyright © 2012 Roving Networks. All rights reserved. Roving Networks is a registered trademark of Roving Networks. Apple Inc., iPhone, iPad, iTunes, Made for iPhone are registered trademarks of Apple Computer. Roving Networks reserves the right to make corrections, modifications, and other changes to its products, documentation and services at any time. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. Roving Networks, Inc. 102 Cooper Court Los Gatos, CA 95032 +1 (408) 395-5300 www.rovingnetworks.com www.rovingnetworks.com Roving Networks assumes no liability for applications assistance or customer’s product design. Customers are responsible for their products and applications which use Roving Networks components. To minimize customer product risks, customers should provide adequate design and operating safeguards. Roving Networks products are not authorized for use in safety-critical applications (such as life support) where a failure of the Roving Networks product would reasonably be expected to cause severe personal injury or death, unless officers of the parties have executed an agreement specifically governing such use. Version 3.21 10/2/2012 16