ensan-hcl/panda

code powering the comma.ai panda

Welcome to panda

panda is the nicest universal car interface ever.

It supports 3x CAN, 2x LIN, and 1x GMLAN. It also charges a phone. On the computer side, it has USB.

It uses an STM32F413.

It is 2nd gen hardware, reusing code and parts from the NEO interface board.

Usage

Python

To install the library:

pip install pandacan

See the Panda class for how to interact with the panda.

For example, to receive CAN messages:

>>> from panda import Panda
>>> panda = Panda()
>>> panda.can_recv()

And to send one on bus 0:

>>> panda.can_send(0x1aa, "message", 0)

Note that you may have to setup udev rules for Linux, such as

sudo tee /etc/udev/rules.d/11-panda.rules <<EOF
SUBSYSTEM=="usb", ATTRS{idVendor}=="bbaa", ATTRS{idProduct}=="ddcc", MODE="0666"
SUBSYSTEM=="usb", ATTRS{idVendor}=="bbaa", ATTRS{idProduct}=="ddee", MODE="0666"
EOF
sudo udevadm control --reload-rules && sudo udevadm trigger

The panda jungle uses different udev rules. See the repo for instructions.

JavaScript

See PandaJS

Software interface support

As a universal car interface, it should support every reasonable software interface.

• User space
• socketcan in kernel (alpha)
• Windows J2534

Directory structure

.
├── board           # Code that runs on the STM32
├── drivers         # Drivers (not needed for use with python)
├── python          # Python userspace library for interfacing with the panda
├── tests           # Tests and helper programs for panda

Programming

See board/README.md

Debugging

To print out the serial console from the STM32, run tests/debug_console.py

Safety Model

When a panda powers up, by default it's in SAFETY_SILENT mode. While in SAFETY_SILENT mode, the buses are also forced to be silent. In order to send messages, you have to select a safety mode. Currently, setting safety modes is only supported over USB. Some of safety modes (for example SAFETY_ALLOUTPUT) are disabled in release firmwares. In order to use them, compile and flash your own build.

Safety modes optionally supports controls_allowed, which allows or blocks a subset of messages based on a customizable state in the board.

Code Rigor

The panda firmware is written for its use in conjuction with openpilot. The panda firmware, through its safety model, provides and enforces the openpilot safety. Due to its critical function, it's important that the application code rigor within the board folder is held to high standards.

These are the CI regression tests we have in place:

• A generic static code analysis is performed by cppcheck.
• In addition, cppcheck has a specific addon to check for MISRA C:2012 violations. See current coverage.
• Compiler options are relatively strict: the flags -Wall -Wextra -Wstrict-prototypes -Werror are enforced.
• The safety logic is tested and verified by unit tests for each supported car variant.
• A recorded drive for each supported car variant is replayed through the safety logic to ensure that the behavior remains unchanged.
• An internal Hardware-in-the-loop test, which currently only runs on pull requests opened by comma.ai's organization members, verifies the following functionalities:
  • compiling the code and flashing it through USB.
  • receiving, sending, and forwarding CAN messages on all buses, over USB.

In addition, we run the pylint and flake8 linters on all python files within the panda repo.

Hardware

Check out the hardware guide

Licensing

panda software is released under the MIT license unless otherwise specified.