The B Series System-on-a-Module (SoM) is a cellular device with support for BLE (Bluetooth LE). It is based on the Nordic nRF52840 micro-controller.
The B Series is designed to be integrated into your circuit board design, plugging a M.2 NGFF connector on your board, allowing the module to be changed or upgraded easily.
- u-blox SARA-R410-02B LTE modem
- LTE Cat M1 module with global hardware support (MVNO support for US only)
- 3GPP Release 13 LTE Cat M1
- Cat M1 bands: 2, 3, 4, 5, 8, 12, 13, 20, 28
- Nordic Semiconductor nRF52840 SoC
- ARM Cortex-M4F 32-bit processor @ 64MHz
- 1MB flash, 256KB RAM
- Bluetooth 5: 2 Mbps, 1 Mbps, 500 Kbps, 125 Kbps
- Supports DSP instructions, HW accelerated Floating Point Unit (FPU) calculations
- ARM TrustZone CryptoCell-310 Cryptographic and security module
- Up to +8 dBm TX power (down to -20 dBm in 4 dB steps)
- NFC-A tag
- On-module additional 4MB SPI flash
- 24 mixed signal GPIO (8 x Analog, 4 x PWM), UART, I2C, SPI
- USB 2.0 full speed (12 Mbps)
- JTAG (SWD) pins
- RGB status pins for LED
- Reset and Mode pins for buttons
- On-module MFF2 Particle SIM
- Two on-module U.FL connectors for external antennas
- M.2 interface
- FCC and PTCRB certified
- RoHS compliant (lead-free)
VCC is used to supply power to the u-blox SARA-R410M cellular module. The recommended input voltage range on this pin is between 3.6V to 4.2V DC. Make sure that the supply can handle currents of at least 2 A.
3V3 is used to supply power to nRF52840, logic ICs, memory, etc. and 3.3v is recommended. VCC input voltage range is between 3V to 3.6V DC. Make sure that the supply can handle currents of at least 150mA.
VBus is connected to the USB detect pin of nRF52840 to enables the USB interface. The recommended input voltage range is between 4.35V to 5.5V DC.
There are two radios on the B402 module. A BLE radio (nRF52840) and a cellular radio (u-blox). We have provided two u.FL connectors to plug in the cellular and BLE antenna. These are required if you wish to use the cellular and BLE. If you do not need BLE, you do not need to connect the BLE antenna.
- The antenna placement needs to follow some basic rules, as any antenna is sensitive to its environment. Mount the antenna at least 10mm from metal components or surfaces, ideally 20mm for best radiation efficiency, and try to maintain a minimum of three directions free from obstructions to be able to operate effectively.
- Needs tuning with actual product enclosure and all components.
- For the BLE antenna, it is recommended to use a 2.4 GHz single-frequency antenna and not a 2.4 GHz + 5 GHz antenna, so as to avoid large gain at the frequency twice of 2.4 GHz which can cause the second harmonic radiation of 2.4 GHz to exceed standards.
|Peripheral Type||Qty||Input(I) / Output(O)|
|Analog (ADC)||8 (max)||I|
There are some optional B402 module specific I/O:
- u-blox USB and VBUS (for u-blox firmware upgrades)
Note: All GPIOs are only rated at 3.3VDC max.
The B402 module has 4 pads at the bottom exposing the SWD interface of the nRF52840. This interface can be used to debug your code or reprogram your E402 bootloader, device OS, or the user firmware. We use 4 pogo-pins connecting to these pads during production for firmware flashing.
- Bootloader (48KB, @0xF4000)
- User Application (128KB, @0xD4000)
- System (656KB, @0x30000)
- SoftDevice (192KB)
- OTA (1500KB, @0x00289000)
- Reserved (420KB, @0x00220000)
- FAC (128KB, @0x00200000)
- LittleFS (2M, @0x00000000)
Pins SOM0 to SOM9 will vary across various SoM modules. For example, cellular-specific pins exists in this range.
Additionally there are RESERVED3 pins, whose functions vary depending on the SoM. For example, nRF52 MCU-based modules use some of these pins for additional ADC and GPIO. They are able to be used as described on the B402, but their function may be be different on future modules.
For maximum cross-module flexibility, you should try to use only the common pins when possible.
|2||VCC||VCC||POWER||System power in, connect to the +LiPo or supply a fixed 3.6-4.2v power.|
|4||VCC||VCC||POWER||System power in, connect to the +LiPo or supply a fixed 3.6-4.2v power.|
|6||VCC||VCC||POWER||System power in, connect to the +LiPo or supply a fixed 3.6-4.2v power.|
|8||VCC||VCC||POWER||System power in, connect to the +LiPo or supply a fixed 3.6-4.2v power.|
|10||3V3||3V3||POWER||System power in, supply a fixed 3.0-3.6v power.|
|11||USB D+||USB D+||IO||Data+ pin of the NRF52840 USB port.|
|12||3V3||3V3||POWER||System power in, supply a fixed 3.0-3.6v power.|
|13||USB D-||USB D-||IO||Data- pin of the NRF52840 USB port.|
|16||VUSB||VUSB||POWER||System power in, USB detect pin for nRF52840. 5V on this pin enables the USB interface.|
|17||NFC1||SOM33||NFC input||P0.9||NFC antenna connection.|
|19||NFC2||SOM43||NFC input||P0.10||NFC antenna connection.|
|20||D1||SCL||IO||P0.27||I2C SCL, and digital only GPIO.|
|22||D0||SDA||IO||P0.26||I2C SDA, and digital only GPIO.|
|23||A0||ADC0||IO||P0.3||Analog input ADC02, and digital GPIO.|
|32||MODE||MODE||IO||P0.11||Connected to the MODE button input, and digital only GPIO.|
|33||A1||ADC1||IO||P0.4||Analog input ADC12, and digital GPIO.|
|34||RESET||RESET||I||Active-low reset input.|
|35||A2||ADC2||IO||P0.28||Analog input ADC22, and digital GPIO.|
|36||D9||TX||IO||P0.6||Primarily used as UART TX, but can also be used as a digital GPIO.|
|37||A3||ADC3||IO||P0.29||Analog input ADC32, and digital GPIO.|
|38||D10||RX||IO||P0.08||Primarily used as UART RX, but can also be used as a digital GPIO.|
|39||AGND||AGND||POWER||System analog ground.|
|40||D3||RESERVED3||IO||P1.1||UART flow control interface CTS, SCL1 (Wire1), SPI1 MOSI, and digital only GPIO.|
|41||A4||RESERVED3||IO||P0.30||Analog input ADC42, and digital GPIO.|
|42||D2||RESERVED3||IO||P1.2||UART flow control interface RTS, SDA1 (Wire1), SPI1 SCK, and digital only GPIO.|
|43||A5||RESERVED3||IO||P0.31||Analog input ADC52, and digital GPIO.|
|44||u-blox USB D+||SOM0||IO||Data+ pin of the R410M USB port.|
|45||A6||RESERVED3||IO||P0.5||Analog input ADC62, and digital GPIO.|
|46||u-blox USB D-||SOM1||IO||Data- pin of the R410M USB port.|
|47||A7||RESERVED3||IO||P0.2||Analog input ADC72, and digital GPIO.|
|48||D8||CS||IO||P1.3||SPI interface CS, and digital only GPIO.|
|49||AGND||AGND||POWER||System analog ground.|
|50||D11||MISO||IO||P1.14||SPI interface MISO, and digital only GPIO.|
|52||D12||MOSI||IO||P1.13||SPI interface MOSI, and digital only GPIO.|
|54||D13||SCK||IO||P1.15||SPI interface SCK, and digital only GPIO.|
|56||GND||GND||POWER||System analog ground.|
|61||RGBR||RED||IO||P0.13||Red pin of the RGB LED.|
|62||D22||GPIO0||IO||P0.24||GPIO0, digital only.|
|63||RGBG||GREEN||IO||P0.14||Green pin of the RGB LED.|
|64||D23||GPIO1||IO||P1.9||GPIO1, digital only.|
|65||RGBB||BLUE||IO||P0.15||Blue pin of the RGB LED.|
|66||D4||PWM0||IO||P1.8||SPI1 MISO, Digital only GPIO, and PWM0.|
|67||SIM_VCC1||SOM53||POWER||Leave unconnected, 1.8V/3V SIM Supply Output from R410M.|
|68||D5||PWM1||IO||P1.10||Digital only GPIO, and PWM1.|
|69||SIM_RST1||SOM63||IO||Leave unconnected, 1.8V/3V SIM Reset Output from R410M.|
|70||D6||PWM2||IO||P1.11||Digital only GPIO, and PWM2.|
|71||SIM_CLK1||SOM73||IO||Leave unconnected, 1.8V/3V SIM Clock Output from R410M.|
|72||D7||PWM3||IO||P1.12||Digital only GPIO, and PWM3.|
|73||SIM_DATA1||SOM83||IO||Leave unconnected, 1.8V/3V SIM Data I/O of R410m with internal 4.7 k pull-up.|
|74||u-blox VBUS||SOM23||IO||USB detect pin for R410M. 5V on this pin enables the u-blox USB interface.|
1These pins are connected to the internal MFF2 SIM and should be left open.
2A0-A7 are 12-bit Analog-to-Digital (A/D) inputs (0-4095).
3SoM-specific and Reserved pins will vary depending on module. They are able to be used on the B402, but their function may be be different on future modules.
Unlike the Boron, the B402 module does not have an on-module RGB system status LED. We have provided its individual control pins for you to connect an LED of your liking. This will allow greater flexibility in the end design of your products.
A detailed explanation of different color codes of the RGB system LED can be found here.
|Supply Input Voltage||VCC||-0.3||+6.0||V|
|Supply Input Voltage||3V3||-0.3||+3.9||V|
|VBUS USB supply voltage||VUSB||-0.3||+5.8||V|
|I/O pin voltage|
|VI/O, VDD ≤ 3.6 V||IO||-0.3||VDD + 0.3||V|
|VI/O, VDD > 3.6 V||IO||-0.3||+3.9||V|
|NFC antenna pin current|
|BT RF input level (52840)||10||dBm|
 Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under recommended operating conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
|Supply Input Voltage||VCC||+3.6||+3.8||+4.2||V|
|Supply Input Voltage||3V3||+3.0||+3.3||+3.6||V|
|VBUS USB supply voltage||VUSB||+4.35||+5.0||+5.5||V|
|Normal operating temperature1||-20||+25||+65||°C|
|Extended operating temperature2||-40||+85||°C|
|Humidity Range Non condensing, relative humidity||95||%|
1 Normal operating temperature range (fully functional and meet 3GPP specifications).
2 Extended operating temperature range (RF performance may be affected outside normal operating range, though module is fully functional)
Boron has two radio modules.
- Bluetooth® 5, 2.4 GHz
- 95 dBm sensitivity in 1 Mbps Bluetooth® low energy mode
- 103 dBm sensitivity in 125 kbps Bluetooth® low energy mode (long range)
- 20 to +8 dBm TX power, configurable in 4 dB steps
|Protocol stack||3GPP Release 13|
|RAT||LTE Cat M1 Half-Duplex|
|LTE FDD Bands||Band 12 (700 MHz)|
|Band 17 (700 MHz)|
|Band 28 (700 MHz)|
|Band 13 (750 MHz)|
|Band 20 (800 MHz)|
|Band 26 (850 MHz)|
|Band 18 (850 MHz)|
|Band 5 (850 MHz)|
|Band 19 (850 MHz)|
|Band 8 (900 MHz)|
|Band 4 (1700 MHz)|
|Band 3 (1800 MHz)|
|Band 2 (1900 MHz)|
|Band 25 (1900 MHz)|
|Band 1 (2100 MHz)|
|LTE TDD bands||Band 39 (1900 MHz)|
|Power class||Class 3 (23 dBm)|
These specifications are based on the nRF52840 datasheet.
|VIH||Input high voltage||0.7 xVDD||VDD||V|
|VIL||Input low voltage||VSS||0.3 xVDD||V|
|VOH,SD||Output high voltage, standard drive, 0.5 mA, VDD ≥1.7||VDD - 0.4||VDD||V|
|VOH,HDH||Output high voltage, high drive, 5 mA, VDD >= 2.7 V||VDD - 0.4||VDD||V|
|VOH,HDL||Output high voltage, high drive, 3 mA, VDD >= 1.7 V||VDD - 0.4||VDD||V|
|VOL,SD||Output low voltage, standard drive, 0.5 mA, VDD ≥1.7||VSS||VSS + 0.4||V|
|VOL,HDH||Output low voltage, high drive, 5 mA, VDD >= 2.7 V||VSS||VSS + 0.4||V|
|VOL,HDL||Output low voltage, high drive,3 mA, VDD >= 1.7 V||VSS||VSS + 0.4||V|
|IOL,SD||Current at VSS+0.4 V, output set low, standard drive, VDD≥1.7||1||2||4||mA|
|IOL,HDH||Current at VSS+0.4 V, output set low, high drive, VDD >= 2.7V||6||10||15||mA|
|IOL,HDL||Current at VSS+0.4 V, output set low, high drive, VDD >= 1.7V||3||mA|
|IOH,SD||Current at VDD-0.4 V, output set high, standard drive, VDD≥1.7||1||2||4||mA|
|IOH,HDH||Current at VDD-0.4 V, output set high, high drive, VDD >= 2.7V||6||9||14||mA|
|IOH,HDL||Current at VDD-0.4 V, output set high, high drive, VDD >= 1.7V||3||mA|
|tRF,15pF||Rise/fall time, standard drivemode, 10-90%, 15 pF load1||9||ns|
|tRF,25pF||Rise/fall time, standard drive mode, 10-90%, 25 pF load1||13||ns|
|tRF,50pF||Rise/fall time, standard drive mode, 10-90%, 50 pF load1||25||ns|
|tHRF,15pF||Rise/Fall time, high drive mode, 10-90%, 15 pF load1||4||ns|
|tHRF,25pF||Rise/Fall time, high drive mode, 10-90%, 25 pF load1||5||ns|
|tHRF,50pF||Rise/Fall time, high drive mode, 10-90%, 50 pF load1||8||ns|
|CPAD_NFC||Pad capacitance on NFC pads||4||pF|
|INFC_LEAK||Leakage current between NFC pads when driven to different states||1||10||μA|
1Rise and fall times based on simulations
Dimensions are in millimeters.
The mating connector is a an M.2 (NGFF) type 4. Note that there are several different key configurations for the M.2, and type 4 is different than is commonly used on SSDs.
We recommend this screw assembly to securely affix the B series SoM to your circuit board. From top to bottom:
- M3 screw, 3mm long
- M3 washer
- M3 standoff, 2.45mm
- Mounting hole, 2.6 mm metal hole, 3.1mm metal ring diameter (picture is of the bottom side of the circuit board)
Note that a hold-down screw is required because the M.2 connector does not have integrated locks and the SoM will pop up if not attached to the base board.
We strongly recommend against placing components under the SOM board because there is not enough height.
The B series contains highly sensitive electronic circuitry and is an Electrostatic Sensitive Device (ESD). Handling an B series without proper ESD protection may destroy or damage it permanently. Proper ESD handling and packaging procedures must be applied throughout the processing, handling and operation of any application that incorporates the B series module. ESD precautions should be implemented on the application board where the B series is mounted. Failure to observe these precautions can result in severe damage to the B series!
The U.FL antenna connector is not designed to be constantly plugged and unplugged. The antenna pin is static sensitive and you can destroy the radio with improper handling. A tiny dab of glue (epoxy, rubber cement, liquid tape or hot glue) on the connector can be used securely hold the plug in place.
The M.2 edge connector is static sensitive and should be handled carefully. The M.2 connector is not designed for repeated removal and insertion of the module.
The B series comes pre-programmed with a bootloader and a user application called Tinker. This application works with an iOS and Android app also named Tinker that allows you to very easily toggle digital pins, take analog and digital readings and drive variable PWM outputs.
The bootloader allows you to easily update the user application via several different methods, USB, OTA, Serial Y-Modem, and also internally via the Factory Reset procedure. All of these methods have multiple tools associated with them as well.
|001||29 Apr 2019||RK||Initial Release|
|002||03 Feb 2020||RK||Fixed number of I2C, SPI, and PWM|
|003||18 Feb 2020||RK||Keep-out diagram M.2 connector was upside-down|