This project communicates between two microcontrollers using the canbus protocol and two canbus breakout boards. From a serial terminal on a pc it can receive a byte over UART, then it sends that bite over SPI to the MCP2515 canbus transceiver, which in turn sends it to the other canbus breakout board. The second microcontroller then reads the data over SPI and transmits it over UART to another serial terminal. This process works exactly the same in the opposite direction.