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.

Block diagram

Block Diagram

Description

Ports Diagram
Num ID Description
1 External Power 5-12 VDC. Minimum power requirements are 5VDC @500mA (when the LiPo battery) or 5VDC @2000mA (without LiPo battery).
2 LiPo Battery connector Plug in the LiPo battery here.
3 SoM USB port This is the module's main USB port that connects to the microcontroller.
4 JTAG connector This can plug directly into the Particle debugger ribbon cable.
5 Battery switch Controls power between the LiPo connector and the charge controller.
6 SoM power switch Controls 3V3 power to the SoM
7 u-blox USB port This USB port connects directly to the u-blox module for firmware updates.
8 Ethernet connector RJ45 connector for twisted pair Ethernet, 10 or 100 Mbit/sec.
9 PoE connector Connect for the Particle PoE adapter for power-over-Ethernet.
10 Cellular antenna Connector for an external SMA connected cellular antenna.
11 Bluetooth antenna Connector for an external SMA connected antenna for Bluetooth networking.
12 TF/SD Card MicroSD card slot.
13 User LED Blue LED connected to pin D7.
14 Reset Button This is same as the RESET button on the Boron.
15 RGB LED System status indicator RGB LED.
16 Mode Button This is the same as the MODE button on the Boron.
17 Expansion Connector Allows easy access to SoM IO pins.
18 Grove Analog Port Connects to Seeed Studio Grove analog and digital boards.
19 Grove I2C Port Connects to Seeed Studio Grove I2C boards.
20 NFC Antenna U.FL connector for an NFC antenna (optional).
21 Jumpers J12 Enable or disable various features on the evaluation board.
22 SoM connector M.2 connector for the B Series SoM.
23 Jumpers J13 Enable or disable various features on the evaluation board.
24 Power Jumpers Enable or disable power from the evaluation board.
25 Charge LED Indicate LiPo is charging.

Jumpers J12

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

Feature Feature Pin SoM Pin B Series Pin
MicroSD SD_MI MISO MISO
SD_CK SCK SCK
SD_MO MOSI MOSI
SD_CS1 PWM1 D5
SD_DECT PWM2 D6
D7 LED USER PWM3 D7
GND GND GND

Jumpers J13

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

B Series Pin SoM Pin Feature Pin Feature
UB_USB_N UB_USB_N u-blox USB
UB_USB_P UB_USB_N
USB_DET UB_VBUS
D8 CS ETH_CS Ethernet
SCK SCK ETH_CLK
MISO MISO ETH_MISO
MOSI MOSI ETH_MOSI
D22 GPIO0 ETH_INT
A6 ADC6 PM_INT Fuel Gauge & PMIC
D0 SDA PM_SDA PMIC
D1 SCL PM_SCL PMIC

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


Power jumpers

Jumper Name
J5 SOM_VCC
J31 SOM_3V3

Expansion connector

B Series Pin SoM Pin SoM Pin B Series Pin
SOM9 NC
SIM_DATA SOM8 PWM3 D7
SIM_CLK SOM7 PWM2 D6
SIM_RST SOM6 PWM1 D5
SIM_VCC SOM5 PWM0 D4
BLUE GPIO1 D23
GREEN GPIO0 D22
RED NC
NC NC
NC GND
NC SCK D13
NC MOSI D12
NC MISO D11
GND CS D8
A7/D20 ADC7 NC
A6/D21 ADC6 NC
A5/D14 ADC5 RTS D2
A4/D15 ADC4 CTS D3
GND RX RX/D10
A3/D16 ADC3 TX TX/D9
A2/D17 ADC2 RESET
A1/D18 ADC1 MODE
A0/D19 ADC0 SDA D0
GND SCL D1
GND NC
GND NC
GND VCC
GND VCC
GND VCC

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).

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

PMIC nRF52 Pin SoM Pin SoM Pin Number
PM_INT P0.05 A6 45
PM_SDA P1.13 D0 22
PM_SCL P1.15 D1 20

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

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

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.

Micro SD nRF52 Pin SoM Pin SoM Pin Number
SD_MISO P1.08 D4 / PWM0 / SPI1 MISO 66
SD_SCK P1.02 D2 / RTS / SPI1 SCK 42
SD_MOSI P1.01 D3 / CTS / SPI1 MOSI 40
SD_CS P1.10 D5 / PWM1 68
SD_DET P1.11 D6 / PWM2 70

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.

W5500 nRF52 Pin SoM Pin SoM Pin Number
ETH_CS P1.03 D8 48
ETH_MISO P1.14 D11 / SPI MISO 50
ETH_SCK P1.15 D13 / SPI SCK 54
ETH_MOSI P1.13 D12 / SPI MOSI 52
RST_N P0.02 A7 (D20) 47
ETH_INT P0.24 D22 62

Using the Grove connectors

J11 nRF52 Pin SoM Pin SoM Pin Number
GND
3V3
ADC2 P0.28 A2 35
ADC1 P0.04 A1 33
J10 nRF52 Pin SoM Pin SoM Pin Number
GND
3V3
SDA P1.13 D0 22
SCL P1.15 D1 20

Evaluation board schematics

PMIC

Fuel gauge


3.3V Regulator

Ethernet

SD Card


Mechanical specifications

Dimensions and weight

Parameter Value
Width 91 mm
Length 142.5 mm
Thickness 15.5 mm
Weight 71.8 grams (including PoE module)

Revision history

Revision Date Author Comments
001 29 Apr 2019 RK Initial Release
002 21 Jan 2020 RK Remove mesh
003 3 Feb 2020 RK Correct pins for SD card
004 20 Jul 2022 RK Correct pins for SD and Ethernet SPI, which are SPI not SPI1
005 9 Sep 2022 RK Correct length
006 19 Jan 2023 RK Correct pins for SD card for version 1.2 board