R N-42 -DS RN42/RN42N Class 2 Bluetooth Module Features • Fully qualified Bluetooth® version 2.1 module, supports version 2.1 + Enhanced Data Rate (EDR) • Backwards-compatible with Bluetooth version 2.0, 1.2, and 1.1 • Postage stamp sized form factor, 13.4 mm x 25.8 mm x 2 mm (RN42) and 13.4 mm x 20 mm x 2 mm (RN42N) • • Low power (26 uA sleep, 3 mA connected, 30 mA transmit) • Measurement and monitoring systems • Industrial sensors and controls UART (SPP or HCI) and USB (HCI only) data connection interfaces. • Medical devices • Computer accessories • Sustained SPP data rates: 240 Kbps (slave), 300 Kbps (master) • HCI data rates: 1.5 Mbps sustained, 3.0 Mbps burst in HCI mode • Embedded Bluetooth stack profiles included (requires no host stack): GAP, SDP, RFCOMM, and L2CAP protocols, with SPP and DUN profile support • Bluetooth SIG certified • Castellated SMT pads for easy and reliable PCB mounting • Certifications: FCC, ICS, CE • Environmentally friendly, RoHS compliant Description The RN42 is also available in a package without an antenna (RN42N). Useful when the application requires an external antenna, the RN42N is shorter in length and has RF pads to route the antenna signal. Applications • Cable replacement • Barcode scanners/readers The RN42 is a small form factor, low power, class 2 Bluetooth radio for designer’s who want to add wireless capability to their products. The RN42 supports multiple interface protocols, is simple to design in, and is fully certified, making it a complete embedded Bluetooth solution. The RN42 is functionally compatible with the RN 41. With its high-performance, on-chip antenna and support for Bluetooth EDR, the RN42 delivers up to a 3 Mbps data rate for distances up to 20 meters. Figure 1. RN42 Block Diagram RN42 Crystal RF Switch BALUN CSR BlueCore-04 External VCC GND GPIO4 GPIO5 GPIO6 USB UART PCM Flash Memory www.rovingnetworks.com Version 2.32r 4/11/2013 1 RN -42 -DS OVERVIEW • Baud rate speeds: 1,200 bps up to 921 Kbps, non-standard baud rates can be programmed • Class 2 radio, 60 feet (20 meters) distance, 4 dBm output transmitter, -80 dBm typical receive sensitivity • Frequency 2,402 ~ 2,480 MHz • FHSS/GFSK modulation, 79 channels at 1-MHz intervals • Secure communications, 128-bit encryption • Error correction for guaranteed packet delivery • Configuration via the local UART and over-the-air RF • Auto-discovery/pairing does not require software configuration (instant cable replacement) • Auto-connect master, I/O pin (DTR), and character-based trigger modes The module’s moisture sensitivity level (MSL) is 1. Table 1 shows the module’s size and weight. Table 1. Module Size & Weight Parameter RN42 RN42N Units Size 13.4 x 25.8 x 2 19 x 13.4 x 2 mm Weight 0.045 0.040 Oz. Tables 2 through 6 provide detailed specifications for the module. Table 2. Environmental Conditions Parameter Value 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 3. Digital I/O Characteristics Min. Typ. Max. Units Input Logic Level Low 3.0 V ≤ VDD ≤ 3.3 V -0.4 - +0.8 V Input Logic Level High 0.7 VDD - VDD + 0.4 V Output Logic Level Low - - 0.2 V Output Logic Level High VDD - 0.2 - - V +0.2 +1.0 +5.0 uA All I/O pins (Except reset) Default to Weak Pull Down www.rovingnetworks.com Version 2.32r 4/11/2013 2 RN -42 -DS Table 4. Electrical Characteristics Parameter Min. Typ. Max. Units 3.0 3.3 3.6 V Supply voltage (DC) Average Power Consumption Radio ON (discovery or inquiry window time), Note (1) 40 mA Connected Idle (no sniff) 25 mA Connected Idle (sniff 100 ms) 12 mA Connected with data transfer 40 45 Deep sleep idle mode 50 26 mA uA Notes: 1. If, in slave mode, there are bursts of radio ON time that vary with the windows. Depending on how you set the windows, that determines your average current. Table 5. Radio Characteristics Parameter Sensitivity at 0.1% BER RF Transmit Power Initial Carrier Frequency Tolerance Freq. (GHz) Min. Typ. Max. Bluetooth Specification Units 2.402 - -80 -86 ≤ -70 dBm 2.441 - -80 -86 2.480 - -80 -86 2.402 0 2 4 2.441 0 2 4 2.480 0 2 4 2.402 - 5 75 2.441 - 5 75 2.480 dBm dBm ≤4 dBm dBm dBm 75 kHz kHz - 5 75 20dB bandwidth for modulated carrier - 900 1,000 ≤ 1000 kHz Drift (Five slots packet) - 15 - 40 kHz Drift Rate - 13 - 20 kHz 2.402 140 165 175 > 140 kHz 2.441 140 165 175 kHz 2.480 140 165 175 kHz 2.402 140 190 - 2.441 140 190 - kHz 2.480 140 190 - kHz ∆f1avg Max Modulation ∆f2avg Min Modulation kHz 115 kHz Table 6. Range Characteristics (Approximate Range In Office Environment) Range RN42 After One Wall 55 feet After Two Walls 60 feet After Three Walls 36 feet The readings shown in Table 6 are approximate and may vary depending upon the RF environment. Bluetooth hops in a pseudo-random fashion over the 79 frequencies in the ISM band to adapt to the interference. Data throughput and range vary depending on the RF interference environment. Figure 2 shows the module’s pinout and Table 7 describes the pins. www.rovingnetworks.com Version 2.32r 4/11/2013 3 RN -42 -DS GND RFPAD GND Figure 2. RN42/RN42N Pinout 27 26 25 GND 1 SPI_MOSI 2 GPIO6 3 GPIO7 24 SPI_MISO 23 SPI_CSB 22 4 RESET GND 1 SPI_MOSI 2 GPIO4 GPIO6 3 21 GPIO5 GPIO7 5 20 GPIO3 SPI_CLOCK 6 19 GPIO2 PCM_CLK 7 18 PCM_SYNC 8 PCM_IN 24 SPI_MISO 23 SPI_CSB 22 GPIO4 4 21 GPIO5 RESET 5 20 GPIO3 SPI_CLOCK 6 19 GPIO2 USB_D- PCM_CLK 7 18 USB_D- 17 USB_D+ PCM_SYNC 8 17 USB_D+ 9 16 UART_CTS PCM_IN 9 16 UART_CTS PCM_OUT 10 15 UART_RTS PCM_OUT 10 15 UART_RTS VDD 11 14 UART_TX VDD 11 14 UART_TX GND 12 13 UART_RX GND 12 13 UART_RX GND AIO0 GPIO8 GPIO9 GPIO10 GPIO11 GND AIO0 GND GPIO8 GPIO9 GPIO10 GND 35 29 34 33 32 31 28 30 GPIO11 35 29 34 33 32 31 28 30 AIO1 RN42N Top View AIO1 RN42 Top View Table 7. Pin Description Pin Name Description Default Voltage (V) 1 GND Ground 2 SPI_MOSI Programming only No Connect 3 3 GPIO6 Set BT master (high = auto-master mode) Input to RN42 with weak pulldown 0 - 3.3 4 GPIO7 Set Baud rate (high = force 9,600, low = 115 K or firmware setting) Input to RN42 with weak pulldown 0 - 3.3 5 RESET Active-low reset. Hold low for low-power operation. Input to RN42 with 1K pullup 6 SPI_CLK Programming only No Connect 7 PCM_CLK PCM interface No Connect 8 PCM_SYNC PCM interface No Connect 9 PCM_IN PCM interface No Connect 10 PCM_OUT PCM interface No Connect 11 VDD 3.3-V regulated power input 12 GND Ground 13 UART_RX UART receive Input Input to RN42 0 - 3.3 14 UART_TX UART transmit output High level output from RN42 0 - 3.3 15 UART_RTS UART RTS, goes high to disable host transmitter Low level output from RN42 0 - 3.3 16 UART_CTS UART CTS, if set high, disables transmitter Low level input to RN42 0 - 3.3 17 USB_D+ USB port Pull up 1.5 K when active 0 - 3.3 18 USB_D- USB port www.rovingnetworks.com 0 0 - 3.3 Version 2.32r 4/11/2013 4 RN -42 -DS Pin Name Description Default Voltage (V) 19 GPIO2 Status, high when connected, low otherwise Output from RN42 0 - 3.3 20 GPIO3 Auto discovery = high Input to RN42 with weak pulldown 0 - 3.3 21 GPIO5 Status, toggles based on state, low on connect Output from RN42 0 - 3.3 22 GPIO4 Set factory defaults Input to RN42 with weak pulldown 0 - 3.3 23 SPI_CSB Programming only No Connect 24 SPI_MISO Programming only No Connect 25 GND Ground for RN42N 26 RF Pad RF pad for RN42N 2729 GND Ground for RN42N 30 AIO0 Optional analog input Not Used 31 GPIO8 Status (RF data Rx/Tx) Output from RN42 0 - 3.3 32 GPIO9 I/O Input to RN42 with weak pulldown 0 - 3.3 33 GPIO10 I/O (remote DTR signal) Input to RN42 with weak pulldown 0 - 3.3 34 GPIO11 I/O (remote RTS signal) Input to RN42 with weak pulldown 0 - 3.3 35 AIO1 Optional analog input Not Used Figure 3 shows the module’s physical dimensions. Figure 3. RN42/RN42N Physical Dimensions All Dimensions Are In mm www.rovingnetworks.com Version 2.32r 4/11/2013 5 RN -42 -DS TYPICAL APPLICATION SCHEMATIC Figure 4 shows a typical application schematic. Because the RN41 and RN42 are functionally compatible, this diagram applies to both modules. Figure 4. Application Schematic www.rovingnetworks.com Version 2.32r 4/11/2013 6 RN -42 -DS DESIGN CONCERNS The following sections provide information on designing with the RN42 module, including radio interference, factory reset, solder reflow profile, connection status, etc. Reset Circuit The RN42 contains a 1k pullup to VCC, and the reset polarity is active low. The module’s reset pin has an optional poweron-reset circuit with a delay, which should only be required if the input power supply has a very slow ramp or tends to bounce or have instability on power up. Often a microcontroller or embedded CPU I/O is available to generate the reset once power is stable. If not, designers can use one of the many low-cost power supervisor chips currently available, such as the MCP809, MCP102/121, and Torex XC61F. Factory Reset Using GPIO4 Roving Networks recommends that designers connect the GPIO4 pin to a switch, jumper, or resistor so it can be accessed. This pin can be used to reset the module to its factory default settings, which is critical in situations where the module has been misconfigured. To reset the module to the factory defaults, GPIO4 should be high on power-up and then toggle low, high, low, high with a 1 second wait between the transitions. Connection Status GPIO5 is available to drive an LED, and it blinks at various speeds to indicate status (see Table 7). GPIO2 is an output that directly reflects the connection state as shown in Table 8. Table 8. GPIO5 Status GPIO5 Status Description Toggle at 1 Hz The module is discoverable and waiting for a connection. Toggle at 10 Hz The module is in command mode. Low The module is connected to another device over Bluetooth. Table 9. GPIO2 Status GPIO2 Status Description High The module is connected to another device over Bluetooth. Low The module is not connected over Bluetooth. HCI Mode Roving Networks offers the Host Controller Interface (HCI) mode in addition to the standard operational mode of its Bluetooth modules (standard mode refers to the on-board stack running on the module). In HCI mode, the on-board stack is bypassed and the module is put in a state that runs the Bluetooth baseband. The HCI provides a command reference interface to the baseband controller and the link manager, and provides access to the hardware status and control registers. This interface provides a uniform method for accessing the Bluetooth baseband capabilities. www.rovingnetworks.com Version 2.32r 4/11/2013 7 RN -42 -DS In this mode, the Bluetooth stack is no longer on-board the module. It is offloaded to the interfacing host processor. The Bluetooth module is used as a radio, performing the lower level MAC functionalities, while the application stack runs on the host processor. Using the module in HCI mode allows designers to implement profiles that are not natively supported on the Bluetooth module. NOTE: HCI mode requires a separate firmware build that must be loaded into the module’s flash at the factory. Is not upgradeable in the field. Roving Networks offers HCI mode in two hardware interfaces: • HCI over UART (RN42HCI-I/RM) • HCI over USB (RN42U-I/RM) HCI over UART In this mode, the hardware interface between the host processor and the Bluetooth module is the UART. You must interface the flow control signals between the host processor and the Bluetooth module for the HCI interface to work. Failure to do so can cause the host processor and the Bluetooth module to become out of sync and break the Bluetooth link. HCI over USB In this mode, the hardware interface between the host processor and the Bluetooth module is the USB. In this architecture, the Bluetooth module is the USB slave and the host processor is the USB host. Using the USB interface offers the advantage of a faster data link between the Bluetooth module and the host processor. With this architecture, it is possible to achieve Bluetooth’s theoretical maximum throughput of 3 Mpbs. Low Power To achieve low-power operation, hold the module’s RESET pin low. With RESET = 0 VDC, the module consumes 35 uA of power. If RESET is left floating or high, the module consumes 3 mA in sleep mode. To obtain the lowest power, the RN42 should be passive (in slave mode and not trying to make connections). Using the SPI Bus to Upgrade the Flash Memory While not required, this bus is very useful for configuring the Bluetooth modules’ advanced parameters. The bus is required when upgrading the module’s firmware. The typical application schematic shown in Figure 4 shows a 6-pin header that can be implemented to gain access to this bus. A minimum-mode version might simply use the SPI signals (4 pins) and obtain ground and VCC from elsewhere in the design. Minimizing Radio Interference When laying out the carrier board for the RN42 module, the areas under the antenna and shielding connections should not have surface traces, ground planes, or exposed vias (see Figure 5). For optimal radio performance, the RN42 module’s antenna end should protrude at least 5 mm beyond any metal enclosure. www.rovingnetworks.com Version 2.32r 4/11/2013 8 RN -42 -DS Figure 5. Minimizing Radio Interference 1.5 mm 1.5 mm 13.4 mm Do not located any surface parts, surface traces, internal traces, or ground planes under the antenna area. 1.5 mm 7.0 mm 1 2 3 4 5 6 7 8 9 10 11 12 Do not locate vias or surface traces under shield connectors (1.5 mm square). 35 1.5 mm 29 33 31 30 34 32 28 24 23 22 21 10 19 18 17 16 15 14 13 Top View 25.6 mm Because the RN42N does not contain an antenna, it does not carry regulatory approvals. If designers use Roving Networks recommended design, they can file for a permissible antenna change and use Roving Networks’ regulatory approvals. The recommended antenna design for the RN42 is a PCB trace antenna. To meet the regulatory compliance information, customers must use the trace pattern shown in Figure 6. Figure 6. Antenna Trace Pattern 140 mil 80 mil Ground Plane Limit 40 mil 40 mil Trace Width Is 20 mil If designers choose to use another antenna, they must go through the regulatory approval process. www.rovingnetworks.com Version 2.32r 4/11/2013 9 RN -42 -DS Antenna Design The pattern from the RF_OUT terminal pad should be designed with 50 ohms impedance and traced with straight lines (see Figure 7). The RF_OUT signal line should not run under or near the RN21 module. The GND plane should be on the side of the PCB to which the module is mounted. GND should be reinforced with through-hole connections and other means to stabilize the electric potential. Figure 7. Antenna Design GND RF_OUT GND Solder Reflow Profile The lead-free solder reflow temperature and times are: • Temperature—230° C, 30 - 40 seconds, peak 250° C maximum • Preheat temperature—165° ± 15° C, 90 to 120 seconds • Time—Single pass, one time www.rovingnetworks.com Version 2.32r 4/11/2013 10 RN -42 -DS COMPLIANCE INFORMATION Table 10 describes the module’s compliance information. Table 10. Compliance Information Category Country Radio Standard USA FCC Part 15 Subpart B: 2008 Class B FCC CRF Title 47 Part 15 Subpart C FCC ID: T9J-RN42 Europe ETSI EN 301 489-1 V1.8.1 ETSI EN 301 489-17 V2.1.1 ETSI EN 300 328 V1.7.1 EMC Canada IC RSS-210 low power comm. device Certification Number: 6514A-RN42 USA FCC CFR47 Part 15 subclass B Europe EN 55022 Class B radiated EN61000-4-2 ESD immunity EN61000-4-3 radiated field EN61000-4-6 RF immunity EN61000-4-8 power magnetic immunity Bluetooth BQB LISTED B014867- SPP and DUN profiles Environmental RoHS RoHS compliant ORDERING INFORMATION Table 11 provides ordering information. Table 11. Ordering Information Part Number Description RN42-I/RM Standard application firmware (SPP/DUN master and slave). RN42HCI-I/RM HCI firmware (HCI over H4 UART). RN42U-I/RM USB firmware (HCI over USB port). RN42N-I/RM Standard application firmware (SPP/DUN master and slave) without antenna. 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 2.32r 4/11/2013 11 RN -42 -DS REVISION HISTORY Version 2.32r 4/11/2013 • Updated the module part numbers. Version 2.31r 10/15/2012 • Updated the GPIO5 status table to correctly show that when GPIO5 is low, it indicates that the module is connected to another device over Bluetooth. • Added information on pins 28 and 29 to the pinout table. Copyright © 2012 2013 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 2.32r 4/11/2013 12