Protocol Definition

TX packet

     0                   1
     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
    *-------------------------------*
    |   Signature   | Time  |CNT|VER|
    *-------------------------------*
    |NUM|VER| Time  |  Yaw  | Pitch |
    | Roll  | X | Y | Z |  unused   |
    | JoyX  | JoyY  | BTNS  | unused|
    *-------------------------------*
    |NUM|VER| Time  |  Yaw  | Pitch |
    | Roll  | X | Y | Z |  unused   |
    | JoyX  | JoyY  | BTNS  | unused|
    *-------------------------------*
    |NUM|VER| Time  |  Yaw  | Pitch |
    | Roll  | X | Y | Z |  unused   |
    | JoyX  | JoyY  | BTNS  | unused|
    *-------------------------------*
    |              ...              |
    |                               |
    *-------------------------------*
    |           checksum            |
    *-------------------------------*

• Common Header
  • Signature(8bytes): magic signature of packet (\x94BEP\x0D\x0A\x1A\x0A)
  • Time(4bytes): unsigned 32bit integer to represent millis after board started
  • CNT(2bytes): number of connected controller
  • VER(2bytes): version (\x00\x01)
• Body (sequence of connected controller)
  • NUM(2bytes): current controller index (starting from 0)
  • VER(2bytes): controller version (\x00\x00)
  • Time(4bytes): unsigned 32bit integer to represent millis after controller started
  • Yaw, Pitch, Roll(4bytes): 32bit float to represent rotation
  • X, Y, Z(2bytes): 16bit signed int to represent world acceleration
  • unused(6bytes): padding
  • JoyX, Y(4bytes): 32bit integer to represent position of joystick (0~1024)
  • BTNS(4bytes): button pressed information
    • 1: up
    • 2: down
    • 4: right
    • 8: left
    • 16: JoyZ
    • 32: unused
    • 64: unused
    • 128: unused
  • unused: reversed for future
  • checksum(16bytes): checksum of packet (TBD)