G36 Tool

Simple companion tool for the G36 line of smartwatches / children trackers. These are sold under various names, such as:

These tracker contain the following hardware:

MT6261 chipset, which is probably used as the GSM modem and application processor
ESP8266, used to detect nearby Wifi networks
The GPS chipset is probably MT3337, as referenced to in the firmware binary.
EM30713 is used as a proximity detector on the back of the watch
A BMA250 3-axis accelerometer is used to detect movement and fall events

Most of this was guessed by reading through the log dumps.

Features

The following log message types are known or decoded to some degree:

0x62: text log message; timestamp, text decoded
0x65: possibly text log message with some extended info; timestamp, text decoded
0x78: possible boot banner; not decoded
0x83: possible SW / HW info message on boot; not decoded

The project currently builds in Visual Studio 2017, but only uses cross platform libraries.

Specify the log file or serial port name on the command line to be decoded. Output will be written to stdout.

To explicitly use a serial port, prefix it with ':'.

The following was learned by reading through serial port dumps.

0x62: text log:
- TickCount (4): ms since boot
- Unknown (4)
- Text Data (x): zero padded, so length % 4 == 0
0x65: extended text log:
- Unknown (4)
- TickCount (4): ms since boot
- Unknown (4)
- Text Data (x): zero padded, so length % 4 == 0
0x78: boot banner (?): sent on boot once
- Unknown (4); example: 08 00 08 00
0x83: boot info / HW/SW info (?): sent on boot once
- Unknown (24); example: 02 00 00 00 10 00 00 00 10 00 00 00 01 00 00 00 01 00 00 00 FF FF FF FF