BTEMP

Based on BTIC CTLV.

Normally will use UDP port 16980. It is intended mostly for LAN use.

Table of Contents Structure Status Flags CTRL Video Stream

Structure

Messages begin with a sync marker, generally with either a TWOCC or FOURCC tag following. If a message has a sync marker followed by a context-dependent marker, data will be compressed and in (Faux)Zlib format.

• 'PING', Ping
  • Optional Data, used to probe for hosts.
  • NodeID:GUID, NodeFlags:U32
  • Identifies the node and its status flags.
• 'PIAK', Ping Acknowledge
  • NodeID:GUID, NodeFlags:U32
  • Identifies the node and its status flags.
• 'RCTR', Register Controller
  • Used to validate controller with robot.
  • NodeID:GUID, NodeAuth:GUID, AuthTag:U16, FmtTag:U16
  • AuthTag: Indicates how authentication is done.
  • FmtTag: Indicates control message format.
• 'RCAK', Register Controller Acknowledge
• 'CTRL', Control Message
  • Depends on control message format.
  • May be encrypted.
• 'IDLE', Idle Keepalive Message.
  • Sent when there is nothing worthwhile to send.
  • Indicates that the other end is still live.
• 'PINS', Sends GPIO Pins Status
  • InMask:U32, OutMask:U32
  • PdmMask:U32, PdmActive:U32
  • InMask indicates which GPIO input pins are set.
  • OutMask indicates which output pins are currently set.
  • PdmMask indicates output pins (for PDM/PWM).
  • PdmActive indicates which pins have PDM output active.
  • For any pins set in PdmMask, a byte follows giving the current target duty-cycle.

Status Flags

• Low 5 bits identify node type:
  • 0=Unknown/Undefined
  • 1=Controller
  • 2=Robot
  • 3-31=Reserved
• Bit 6/7: Response Request
  • 0=Default Response (PING/PIAK)
  • 1=No Response (PING only)
  • 2/3=Reserved

CTRL

• Impulse1:u32
  • Bits 0-9, Indicate numeric keypad bits digits.
  • Bits 10-13, Up, Down, Left Right keys.
• Impulse2:u32
• Throt1,Throt2,Throt3,Throt4:byte
  • Give 4 throttle controls as bytes.

Video Stream

Markers

• 'VS1G': Frame Segment (Uncompressed)
• 'VZ1G': Frame Segment (Deflate / BTLZH Compressed)
• 'VS1H': Frame Segment (BTIC1H)

'SH': Segment Header

• streamId:byte, stream ID number
• msgFlag:byte, message flags
• frameNumber:u16, frame number (modulo)
• startBlock:u16, low bits of starting block number for segment
• endBlock:u16, low bits of ending block number for segment.
• startBlockHigh:byte, high bits of starting block number
• endBlockHigh:byte, high bits of ending block number
  • 24 bits allows a max resolution of 16384x16384.
  • 20 bits would limit it to 4096x4096.
  • 16 bits would limit it to 1024x1024.
  • Though, yes, all are bigger than 640x480 or 320x240...

Image Data Marker:

• BTIC1G
• BTIC1H