Panda#

The panda is comma.ai’s open-source CAN bus interface. It connects your car’s CAN buses to a computer (or comma device) over USB, allowing openpilot to read vehicle data and send control commands.

Built into comma devices#

In the early days of openpilot, the panda was a separate USB dongle (white panda, grey panda, black panda) that you plugged into an EON or a laptop. Today, the panda is built directly into the comma four, comma 3X, and comma three — no separate device needed. When you connect your comma device to a car harness, the internal panda handles all CAN communication automatically.

Standalone Red Panda#

The red panda is the latest standalone version, available for purchase separately. It’s useful for:

CAN bus development and debugging — connect to your car with a laptop to monitor and analyze CAN traffic
Viewing live data in Cabana — comma’s web-based CAN signal viewer and DBC editor
Reverse engineering — decode CAN messages from new vehicles or new signals
Running openpilot on a PC — for development without a comma device

The red panda connects via USB-C and supports up to 3 CAN buses simultaneously. The hardware and firmware are fully open source at github.com/commaai/panda.

Panda LED colors#

White: CAN send enabled
Red (fades in and out): Heartbeat — power is on
Green (fast blink): Bad firmware or firmware flashing in progress
Blue (static): CAN traffic detected
Blue (fades in and out): Power saving mode