Protocol¤
Board comunicates with the control board over SPI.
Display board is slave, controling board is host,
Command code¤
8-bit value determining the command
| Code | Description |
|---|---|
| 0x00 | Ignore |
| 0x0X | Ping |
| 0x1X | Screen |
| 0x2X | USB |
Packet lenght¤
16-bit / uint16 number determining the lenght in bytes of the comming data (not including the command code or packet lenght)
TODO - little/big endian
Data¤
Predetermined lenght of bytes representing what should be done / what happened. For example the display buffer or usb device feedback.
Padding (optional)¤
Few bytes as a padding to make sure the recieving device recieves the correct amount of data