| Msg Type | MCU message | Pi message | |
|---|---|---|---|
| Button event | 1 | Short click: 0x01 | ACK: 0xF1 |
| 1 | 3 seconds press: 0x02 (power on) | No ACK | |
| 1 | 6 seconds press: 0x03 (power off) | Confirm: 0xF3, Cancel: 0xFC | |
| 1 | 10 seconds press: force poweroff (no message) | No ACK | |
| Battery event | 2 | 2 bytes message, send every second, unit in mv | |
| Charge event | 3 | Charging: 0x4 | ACK: 0xF4 |
| 3 | Not charging: 0x5 | ACK: 0xF5 | |
| Version event | 4 | 0xF6 | |
| Cutoff event | 5 | 0xF7 |
| header | msg type | length of payload | payload | crc |
|---|---|---|---|---|
| 0xa55a | 1 byte | 2 bytes | sum of all other bytes |