panda/README.md

# Welcome to panda

[panda](http://github.com/commaai/panda) is the nicest universal car interface ever.

<a href="https://comma.ai/shop/products/panda-obd-ii-dongle"><img src="https://github.com/commaai/panda/blob/master/panda.png">

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](http://www.st.com/en/microcontrollers/stm32f413-423.html?querycriteria=productId=LN2004).

It is 2nd gen hardware, reusing code and parts from the [NEO](https://github.com/commaai/neo) interface board.

![panda tests](https://github.com/commaai/panda/workflows/tests/badge.svg)
![panda drivers](https://github.com/commaai/panda/workflows/drivers/badge.svg)

## Usage

### Python

To install the library:
``` bash
pip install pandacan
```

See [the Panda class](https://github.com/commaai/panda/blob/master/python/__init__.py) for how to interact with the panda.

For example, to receive CAN messages:
``` python
>>> from panda import Panda
>>> panda = Panda()
>>> panda.can_recv()
```
And to send one on bus 0:
``` python
>>> panda.can_send(0x1aa, "message", 0)
```
Note that you may have to setup [udev rules](https://github.com/commaai/panda/tree/master/drivers/linux) for Linux, such as
``` bash
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
```

### JavaScript

See [PandaJS](https://github.com/commaai/pandajs)


## Software interface support

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

- [User space](https://github.com/commaai/panda/tree/master/python)
- [socketcan in kernel](https://github.com/commaai/panda/tree/master/drivers/linux) (alpha)
- [Windows J2534](https://github.com/commaai/panda/tree/master/drivers/windows)

## 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](https://github.com/commaai/openpilot). The panda firmware, through its safety model, provides and enforces the
[openpilot safety](https://github.com/commaai/openpilot/blob/devel/SAFETY.md). 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](https://github.com/commaai/panda/actions) we have in place:
* A generic static code analysis is performed by [cppcheck](https://github.com/danmar/cppcheck/).
* In addition, [cppcheck](https://github.com/danmar/cppcheck/) has a specific addon to check for [MISRA C:2012](https://www.misra.org.uk/MISRAHome/MISRAC2012/tabid/196/Default.aspx) violations. See [current coverage](https://github.com/commaai/panda/blob/master/tests/misra/coverage_table).
* Compiler options are relatively strict: the flags `-Wall -Wextra -Wstrict-prototypes -Werror` are enforced.
* The [safety logic](https://github.com/commaai/panda/tree/master/board/safety) is tested and verified by [unit tests](https://github.com/commaai/panda/tree/master/tests/safety) for each supported car variant.
* A recorded drive for each supported car variant is [replayed through the safety logic](https://github.com/commaai/panda/tree/master/tests/safety_replay)
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](https://www.pylint.org/) and [flake8](https://github.com/PyCQA/flake8) linters on all python files within the panda repo.

## Hardware

Check out the hardware [guide](https://github.com/commaai/panda/blob/master/docs/guide.pdf)

## Licensing

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