2015 Protocol

Similarities:

• UDP based

Differences

• Packets are much smaller. ~10 bytes on average compared to 1024.
• More than just 2 packets exist now. There are at least 4 packets that extend information.
• No CRC32 checking

Tested Conditions on 1/10/15

• Windows 8.1
• Team 178
• Getting Started Example Robot Java Project
• Timezone EST, no Daylight Savings
• No joysticks or custom HID

Client to roboRIO

General Packet

Sent every: 0.02s (50 Hz)
Sends to port: 1110
Length: 6 bytes (Appears to be with tested conditions)
Bytes:

• 1-2: Ping
• 3: Protocol Version (01)
• 4: Control byte
• 00 when Driver Stations starts. Probably means disabled.
• 04 during TeleOperated.
• 06 during Autonomous.
• 05 during Test.
• 80 during Emergency Stop
• 5: Request Byte
• 10 during normal conditions
• 11 to request version
• 12 to request usage data
• 14 during Reboot Robot Code and until next roboRIO response
• 18 during Reboot roboRIO and until next roboRIO response
• 6: Alliance and position
• 00 for red 1
• 01 for red 2
• 02 for red 3
• 03 for blue 1
• 04 for blue 2
• 05 for blue 3

The rest of the packet is composed of Joystick structures, these are dynamically sized so they cannot be assigned to specific bytes. The rest of the packet consists of N Joystick structures, where N is the number of joysticks registered with your DriverStation. A single Joystick structure has the following fields.

• Joystick

• Size of this Joystick structure, excluding this byte

• Section Header: Joystick : always 0x0c

• Number of axis'

• Axis values, one byte per axis

• Number of buttons

• Button states, each button is represented as 2^button. The states is the sum of all the calculated values of the buttons:

  • If a button is not pressed, its value will be 0
  • Button 0 is represented as 1 (2^0 = 1)
  • Button 1 is represented as 2 (2^1 = 2)
  • Button 2 is represented as 4 (2^2 = 4)
  • Button 9 is represented as 512 (2^9 = 512)
  • If buttons 0 and 1 are pressed, we must send 3 (1 + 2 = 3)
  • If buttons 4 and 5 are pressed, we must send 48 (2^4 + 2^5 = 16 + 32 = 48)

• Number of POV controls

• Current angle of each POV control, range 0-360 or -1 when inactive. Two bytes per control.

Connected Packet

Appears to be sent twice after the first roboRIO response and after a roboRIO reboot. Length: 27 bytes (Appears to be with Example Java Project)
Bytes:

• 1-2: Ping
• 14-27: timezone in ASCII (EST5EDT during testing)

General Packet (with 1 joystick)

Sent every: 0.02s (50 Hz)
Length: 24 bytes (Appears to be with tested conditions)
Bytes:

• 1-6: Information from general packet

roboRIO to Client

General Packet

One of the expanded packets will replace this one when their period or appropriate time comes.
Sends to port: 1150
Sent every: 0.02s (50 Hz). Length: 8 bytes (Appears to be with tested conditions)
Bytes:

• 1-2: Pong
• 3: Protocol Version (01)
• 4: Echo/confirmation of control byte.
• 5: User program status.
• (status & 0x01) != 0: Disabled?
• (status & 0x02) != 0: Teleoperated?
• (status & 0x04) != 0: Autonomous?
• (status & 0x08) != 0: Test?
• (status & 0x10) != 0: roboRIO?
• (status & 0x20) != 0: User code present?
• 6: XX in XX.YY for battery voltage in hex (ex: 10 of 10.38)
• 7: YY in XX.YY for battery voltage in hex (ex: 38 of 10.38)
• Note: lopsided98 has noticed that this value may be larger than 100 on occasion, which means the information here for this value may not be correct.
• 8: Request byte.
• 00: Nothing
• 01: The robot is requesting the current time and date

24 byte Expanded Packet

Sent every: 1s (1 Hz)
Length: 24 bytes (Appears to be with tested conditions)
Bytes:

• 1-8: Information from general packet
• 9: Unknown. 0f with tested conditions.
• 10: Unknown. 0e with tested conditions.
• 11-21: Unknown. All 00 with tested conditions.
• 22: Unknown. 01 with tested conditions.
• 23: Unknown. 00 with tested conditions.
• 24: Unknown. 80 with tested conditions.

43 byte Expanded Packet

This packet is sent 0.1s (5 packets) after the 24 byte expanded packet
Sent every: 1s (1 Hz)
Length: 43 bytes (Appears to be with tested conditions)
Bytes

• 1-8: Information from general packet

18 byte Expanded Packet #1

This packet is sent 0.1s (5 packets) after the 43 byte expanded packet
Sent every: 1s (1 Hz)
Length: 18 bytes (Appears to be with tested conditions)
Bytes:

• 1-8: Information from general packet
• 9: Unknown 09 with tested conditions.
• 10: Unknown. 04 with tested conditions.
• 11-14: Unknown. 00000000 with tested conditions.
• 15: Unknown. 10 with tested conditions.
• 16: Unknown. 39 with tested conditions.
• 17-18: Unknown. 0000 with tested conditions.

18 byte Expanded Packet #2

This packet is sent 0.1s (5 packets) after the 18 byte expanded packet #1.
Sent every: 1s (1 Hz)
Length: 18 bytes (Appears to be with tested conditions)
Bytes:

• 1-8: Information from general packet
• 9: Unknown 09 with tested conditions.
• 10: Unknown. 06 with tested conditions.
• 11-14: Unknown. 00000000 with tested conditions.
• 15: Unknown. 04 with tested conditions.
• 16: Unknown. 19 with tested conditions.
• 17: Unknown. 10 with tested conditions.
• 18: Unknown. 00 with tested conditions.