B-Series Evaluation board

This is a simple breakout board for Particle's B series of cellular IoT modules. It breaks out all of its pins via easy to use headers. The board features a redundant USB port, connector for the LiPo battery, a barrel jack power connector, buttons, RGB LED, and charge status LED.

The Eagle CAD design files, Gerber files, and bill of materials can be found in the SoM eval board GitHub repository.

This evaluation board is intended to be used with the B-SoM (B404X, B404, B402, B524, B523) not the M-SoM (M404, M524, M635) and a new M.2 breakout board will be available in the future for the M SoM.

Block diagram

Description

Powering the board

The B-Series Eval Board can be powered by:

• There are two USB Micro B connectors on the eval board, be sure to use connector 3 "SOM USB".
• The B524/B523 require a LiPo battery when powering by USB due to the higher current requirements of 2G/3G. The B404X/B404/B402 (LTE Cat M1) can be powered by USB without a battery.
• When powering by VIN (barrel connector), 5-12 VDC is recommended, but up to 17 VDC can be supplied.
• Minimum power requirements are 5VDC @500mA (when using the LiPo battery) or 5VDC @2000mA (without LiPo battery).
• If purchasing a LiPo battery from a 3rd-party supplier, beware as the polarity of the JST-PH connector is not standardized and may be reversed. Permanent damage to the eval board can occur if powered by reverse polarity on the JST connector. See the battery guide for additional information.
• This board is not recommended for use with the M-SoM, however it can be used if you power it using the VIN barrel connector with a 12 watt power supply, 6V minimum.

Jumpers J12

These pins are intended to be connected across using removable two-pin jumpers to connect features on the board to standard ports.

Jumpers J13

These pins are intended to be connected across using removable two-pin jumpers to connect features on the board to standard ports.

For more information about Ethernet, see the application note AN037 Ethernet.

Power jumpers

PWM Differences

On the B-Series SoM, pins D4, D5, D7, A0, A1, A6, and A7 can be used for PWM. Pins are assigned a PWM group. Each group must share the same frequency and resolution, but individual pins in the group can have a different duty cycle.

• Group 2: Pins A0, A1, A6, and A7.
• Group 1: Pins D4, D5, and D6.
• Group 0: Pin D7 and the RGB LED. This must use the default resolution of 8 bits (0-255) and frequency of 500 Hz.

On Gen 3 Feather devices (Argon, Boron, Xenon), pins A0, A1, A2, A3, D2, D3, D4, D5, D6, D7, and D8 can be used for PWM. Pins are assigned a PWM group. Each group must share the same frequency and resolution, but individual pins in the group can have a different duty cycle.

• Group 3: Pins D2, D3, A4, and A5.

• Group 2: Pins A0, A1, A2, and A3.

• Group 1: Pins D4, D5, D6, and D8.

• Group 0: Pin D7 and the RGB LED. This must use the default resolution of 8 bits (0-255) and frequency of 500 Hz.

These rules also apply to tone() (square wave with 50% duty cycle), however since each group must share the same frequency you can only generate two different simultaneous tones of different frequencies on the B-Series SoM. You cannot generate tone on group 0.

Basic setup

The basic setup for the B series to be operational is shown below:

• Plug the cellular antenna into the U.FL connector labeled CELL on the SoM. Remember never to power up this board without the antenna being connected. There is potential to damage the transmitter of the u-blox module if no antenna is connected.
• If you are going to use mobile app setup or BLE, connect the 2.4 GHz antenna (the smaller one) to the BT U.FL connector on the SoM.
• Connect power the USB (3) or a LiPo battery (4).
• Turn on the appropriate power switches (5).

Using the PMIC and fuel gauge (recommended)

There is support for bq24195 PMIC and MAX17043 fuel gauge in Device OS so you don't need to add any additional configuration.

It requires these jumpers, which should be installed at the factory:

• ADC6 to PM_INT
• SDA to PM_SDA
• SCL to PM_SCL

If you are not using the PMIC be sure to remove the jumper if you need use pin A6 as an analog input or GPIO.

Power consumption

We do not recommend using the B-Series eval board for power consumption measurements. It's impossible to completely disconnect the Wiznet W5500 Ethernet interface without removing the chip from the board. This will result in significantly higher power consumption measurements than you would have in most applications.

Using the MicroSD card

To use the MicroSD card, you must add the jumpers for the SD_ pins.

You will normally use this with the SdFat library.

With the jumpers installed, it will use the secondary SPI (SPI1) and pin D5 as the chip select. You cannot use D2, D3, D4, D5, and D6 as GPIO for your own (non-SD card) use.

Note that SD_DET (D6 / PWM2) is an output. It's pulled high with a 47K resistor and driven low by a mechanical switch when a SD card is inserted. Be sure to remove the jumper if you are using D6 as regular GPIO.

Using ethernet

To use Ethernet, you must add the jumpers:

• CS to ETH_CS
• SCK to ETH_SCK
• MISO to ETH_MISO
• MOSI to ETH_MOSI
• GPIO0 to ETH_INT

With the jumpers installed, it will use the primary SPI and pins D8 as the chip select and D22 as the interrupt pin. You cannot use pins D8, D20, D22, or primary SPI (MISO, MOSI, SCK) as GPIO for your own (non-Ethernet) use. You can share SPI with other SPI peripherals that have libraries that correctly implement SPI transactions.

Using the Grove connectors

Expansion header

1 GND

2 VCC

3 GND

4 VCC

5 GND

6 VCC

7 GND

8 3V3

9 GND

10 SOM10

11 SOM6

12 SOM11

13 SOM7

14 D1

15 A0

16 D0

17 A1

18 MODE

19 A2

20 RST

21 A3

22 TX

23 GND

24 RX

25 A4

26 D3

27 A5

28 D2

29 A6

30 SOM0

31 A7

32 SOM1

33 GND

34 D8

35 SOM14

36 MISO

37 SOM15

38 MOSI

39 SOM16

40 SCK

41 SOM17

42 GND

43 SOM18

44 SOM12

45 RGBR

46 SOM13

47 RGBG

48 D22

49 RGBB

50 D23

51 SOM5

52 D4

53 SOM6

54 D5

55 SOM7

56 D6

57 SOM8

58 D7

59 GND

60 SOM9

Evaluation board schematics

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Mechanical specifications

Dimensions and weight

Revision history