Tracker SoM Evaluation Board(pre2)

This is a preliminary datasheet and is subject to change

This is a breakout board for Particle's Tracker SoM. The Tracker SoM Cellular GNSS module is a castellated system-on-a-module that can either be reflow soldered to your own custom base board, or can be used in this evaluation board, or the carrier board.

Block Diagram

Block Diagram


Num ID Description
1 GNSS USB u-blox GNSS USB connection
2 CELL USB Quectel cellular modem USB connection
3 JTAG JTAG/SWD debugging connector for nRF52 MCU
4 NFC NFC antenna connection for NFC tag feature
5 MODE MODE button
6 RGB RGB status LED
7 RESET RESET button
8 MCU USB nRF52 MCU USB for debugging. Can also power the SoM.
9 STAT LED Charge status indicator.
10 J9 STAT LED jumper. Normally installed, remove to disable STAT LED.
11 3V3 LED Power LED, indicates 3.3V supply is enabled.
12 J8 3V3 LED jumper. Normally installed, remove to disable 3V3 LED.
13 VIN External power 5-12 VDC
14 LiPo JST-PH connector for LiPo battery
15 S4 Battery switch
16 S6 SoM power switch
17 Expansion connector
18 J10 Grove connector (A0, A1 or I2C)
19 J11 Grove connector (A2, A3)
20 S5 RTC battery switch
21 RTC battery Optional battery
22 J4 CAN data connection and 3.3V power output
23 J5 JTAG power jumper. Install to allow the MCU to be powered by the JTAG port.

Powering the Tracker SoM Evaluation Board

There are several options for powering the evaluation board:

The MCU USB connector. If using a laptop with a 500 mA USB port, you should also use the LiPo battery. With a 2A tablet charger, you can power only by USB.

The VIN connector (5-12 VDC). This is useful with an external power supply. Switch S6 is the power switch.

The LiPo connector. This is typically used with a LiPo battery. Use switch S4 to enable the battery.

USB connectors

There are three USB connectors on the evaluation board, however you most commonly will only use the MCU USB connector.

The MCU USB connector is connected to the nRF52 MCU and can be used for Serial debugging, flashing code, and setup by USB. It can also power the AssetTracker SoM. If using a laptop with a 500 mA USB port, you should also use the LiPo battery. With a 2A tablet charger, you can power only by USB.

The GNSS USB connector is connected to the u-blox NEO-M8U GNSS. It can be used for firmware upgrades or with the u-blox u-center application.

The CELL USB connector is connected to the Quectel cellular modem. It can be used for firmware upgrades.

LED Indicators

The STAT LED indicates the charge status:

  • Off: Not charging or no power
  • On: Charging
  • Blinking: Charge fault
  • Flickering: No battery

Jumper J9 disconnects the charge status LED.

The 3V3 LED indicates that the 3.3V MCU power supply is enabled. Jumper J8 disconnects the power LED.

Expansion Connector

Left Description Left Right Right Description
Ground GND GND Ground
PMIC power out PMID LI+ LiPo battery
PMIC thermistor TS VBUS nRF52 USB power
3.3V Out 3V3 STAT PMIC charge status
Unused SOM44 VIN Power input 5-12V
Ground GND GND Ground
A4, D4, SPI MOSI A4 A0 A0, D0, Wire SDA
A5, D5, SPI MISO A5 A1 A1, D1, Wire SCL
A6, D6, SPI SCK A6 A2 A2, D2, Serial1 CTS
A7, D7, SS, WKP A7 A3 A3, D3, Serial1 RTS
Unused SOM37 SOM59 Unused
Unused SOM36 SOM60 Unused
Unused SOM35 SOM61 Unused
Unused SOM34 SOM62 Unused
3.3V Out 3V3 3V3 3.3V Out
Ground GND AGND Analog Ground
MODE button MODE MCU_TX Serial1 TX, GPIO D8
RGB Status LED Red R RTC_BAT RTC battery
RGB Status LED Green G RTC_BTN RTC wake button
RGB Status LED Blue B SOM76 Unused
NFC Tag Antenna NFC1 SOM77 Unused
NFC Tag Antenna NFC2 SOM78 Unused
Unused SOM21 SOM79 Unused
Unused SOM20 SOM80 Unused
Unused SOM19 SOM81 Unused
Unused SOM18 SOM82 Unused
3.3V Out 3V3 3V3 3.3V Out
ESP32 Serial TX WIFI_TXD CELL_RX Cellular serial RX
ESP32 boot mode WIFI_BOOT CELL_TX Cellular serial TX
ESP32 enable WIFI_EN CELL_RI Cellular ring indicator
Unused SOM9 GNSS_TIME_PULSE GNSS time pulse or fix indicator
Ground GND GND Ground

Basic Setup

The basic setup for the Tracker SoM Eval Board 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 cellular module if no antenna is connected.
  • Connect power the MCU USB (8), VIN (13), or a LiPo battery (14).
  • Turn on the appropriate power switches (15 and/or 16).

Evaluation Board Schematics

To be provided at a later date.

Mechanical specifications

To be provided at a later date.

Dimensions and weight

Parameter Value Units
Width 97 mm
Length 164 mm
Thickness 14 mm
Weight g

Weight will be provided at a later date.

Revision history

Revision Date Author Comments
pre1 31 Mar 2020 RK Preview Release
pre2 12 May 2020 RK Added partial dimensions