tracker 328

A small tracker board using three main components: ATMEGA328p, ATGM336, RFM95. Additionally ADXL345 as 3-axis accellerometer. You can use LoraWAN, but it makes the m328 RAM crowded. Therefore some tricks needed. Arduino IDE sketch included.

PCB variations in this project:
PCB_tracker328p                             => (17.3x49.3mm)
PCB_tracker328p_compact         => (17.4x35mm)

You can see the pinout in schematic and arduino test code.

If you want to check BOM, you should do that in editor mode with open the required version of PCB (some components may not listed in this page). ATMEGA328 is quite outdated for LoRaWAN (LMIC library), but the attached code worked for me.

FOR RAM SHORTAGE

Strongly recomended to use MiniCore bootloader, with LTO mode in Arduino (be careful at clock select).
Older Arduino LMIC library by Matthijs Kooijman: https://github.com/matthijskooijman/arduino-lmic 
MiniCore: https://github.com/MCUdude/MiniCore

Without voltage regulator use this:

https://www.instructables.com/Secret-Arduino-Voltmeter/

Power consumption estimation in sleep mode (based on component datasheets):
GPS         10uA
RFM95        1uA
ATMEGA328p@8MHz    ~3uA
MCP1702T        2uA
voltage divider    ~1uA
ADXL        on: 23uA?; off: 0.1uA
estimated total with ADXL: ~40uA
estimated total without ADXL: ~17uA

measured consumption (total) with multimeter:
with ADXL off (in sw):    18uA
with ADXL on:    59uA

Perhaps there are some options to reduce power consumption in software incase of ADXL use (ADXL bandwidth or setLowPower mode, set library to observe less activity, etc.)
Additionally you can reduce the consumption, if the GPS signal indicator LED removed.

If you need help, fell free to send a message to me, or leave a comment here.

This project is free (GPL 3.0). Use at your own risk!