It uses an [STM32F413](http://www.st.com/en/microcontrollers/stm32f413-423.html?querycriteria=productId=LN2004) for low level stuff and an [ESP8266](https://en.wikipedia.org/wiki/ESP8266) for Wi-Fi. They are connected over high speed SPI, so the panda is actually capable of dumping the full contents of the busses over Wi-Fi, unlike every other dongle on amazon. ELM327 is weak, panda is strong.
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.
When compiled from the [EON](https://comma.ai/shop/products/eon-gold-dashcam-devkit) or [comma two](https://comma.ai/shop/products/comma-two-devkit) dev kits, the panda FW is configured and optimized (at compile time) for its use in
[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.
* 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 on board and pedal Makefiles.
* 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)
* 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 in various configuration and flashing it both through USB and WiFi.
* Receiving, sending and forwarding CAN messages on all buses, over USB and WiFi.
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.