Get Xiaomi Mi Composition Scale 2 weight and publishing to fitbit

Requirements

• cargo
• pkg-config (for linux)
• libssl-dev (for linux)
• libdbus-1-dev (for linux)

sudo make install

Usage

cp variables-template.json variables.json
vim variables.json
make run
# make debug

Autostart

sudo make add-service
sudo make enable-service

Help

get dev mac address:

sudo hcitool lescan

if u have troubleshoots, try restart u bluetooth/adapter

sudo hciconfig hci0 reset
sudo invoke-rc.d bluetooth restart

Reverse Engineering RAW Schema for Mi Composition Scale 2

Payload format (year, impedance and weight are little endian):

• bytes 0 and 1: control bytes
• bytes 2 and 3: year
• byte 4: month
• byte 5: day
• byte 6: hours
• byte 7: minutes
• byte 8: seconds
• bytes 9 and 10: impedance
• bytes 11 and 12: weight (/100 for pounds and catty, /200 for kilograms)

Control bytes format (LSB first):

• bit 0: unknown
• bit 1: unknown
• bit 2: unknown
• bit 3: unknown
• bit 4: unknown
• bit 5: unknown
• bit 6: unknown (always 1 on my scale)
• bit 7: is pounds
• bit 8: is empty load (no weight on scale)
• bit 9: is catty
• bit 10: is stabilized (weight confirmed, that's also when the weight on scale blinks)
• bit 11: unknown
• bit 12: unknown
• bit 13: unknown (always 1 on my scale)
• bit 14: have impedance (impedance bytes are set correctly)
• bit 15: unknown