Tracker SoM Evaluation board(001)

Evaluation Board

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


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-C for debugging or power.
9 J8 3V3 LED jumper. Normally installed, remove to disable 3V3 LED.
10 3V3 LED Power LED, indicates 3.3V supply is enabled.
11 STAT LED Charge status indicator.
12 J9 STAT LED jumper. Normally installed, remove to disable STAT LED.
13 VIN External power 3.9-17 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 CAN power jumper (selects 3.3V or 5V)

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 (3.9 to 17 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.

CAN connector

The four-position screw terminal connector (J4) allows connection to CAN bus devices.

Pin Label Description
1 CAN_H CAN Bus H or +
2 CAN_L CAN Bus L or -
3 GND Ground
4 CAN_VCC 3.3V or 5V

The CAN bus connection includes the 120 ohm termination resistor and ESD protection.

The CAN_VCC jumper (J5) allows the selection of the voltage on the CAN connector.

  • Left position: 3.3V
  • Right position: 5V

The 5V power supply is powered by a boost converter and can be turned on and off by software.

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 3.9 - 17 VDC
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

Tracker SoM

Block Diagram


Block Diagram

Power switches

Block Diagram

Expansion connector

Block Diagram


Block Diagram

Design files

The Tracker SoM Evaluation board is open-source and the Eagle CAD design files are available in GitHub:

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.

Ordering information

SKU Description Region Modem EtherSIM Lifecycle Replacement
T404MKIT Tracker SoM LTE M1 (NorAm, EtherSIM) Evaluation Kit, [x1] NORAM BG96-MC GA
T524MKIT Tracker SoM LTE CAT1/3G/2G (Europe, EtherSIM) Evaluation Kit, [x1] EMEAA EG91-EX GA
T523MKIT Tracker SoM LTE CAT1/3G/2G (Europe) Evaluation Kit, [x1] EMEAA EG91-EX NRND T524MKIT
T402MKIT Tracker SoM LTE M1 (NorAm) Evaluation Kit, [x1] NORAM BG96-MC Deprecated T404MKIT

†EMEAA: Selected countries in Europe, Middle East, Africa, and Asia, including Australia and New Zealand. See the cellular carrier list for more information.

Product handling

ESD precautions

The Tracker SoM contains highly sensitive electronic circuitry and is an Electrostatic Sensitive Device (ESD). Handling an module 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 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 module!


The U.FL antenna connectors are 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.



This device must be treated as Waste Electrical & Electronic Equipment (WEEE) when disposed of.

Any WEEE marked waste products must not be mixed with general household waste, but kept separate for the treatment, recovery and recycling of the materials used. For proper treatment, recovery and recycling; please take all WEEE marked waste to your Local Authority Civic waste site, where it will be accepted free of charge. If all consumers dispose of Waste Electrical & Electronic Equipment correctly, they will be helping to save valuable resources and preventing any potential negative effects upon human health and the environment of any hazardous materials that the waste may contain.

Revision history

Revision Date Author Comments
pre1 31 Mar 2020 RK Preview Release
pre2 12 May 2020 RK Added partial dimensions
001 29 Jun 2020 RK First release