CAN bus STM32F407VG reprogramming using a PIC microcontroller and the built-in UART bootloader

Abstract

This project details a solution to reprogram the electronic control units installed in a Formula Student racing car. The proposed solution is based on CAN bus communications to flash the electronic control units as fast as possible. This report goes through an antecedent project that tried to find a solution using the part of the bootloader that interacts directly with CAN peripherals, which was not completely satisfactory. In this project solution, we use the part of the bootloader that interacts with the UART peripheral. To “translate” the messages from USART to CAN and vice-versa, we propose to use an intermediary microcontroller working as a gateway between the CAN bus and the UART (of each ECU). In the following pages you can find the code of the intermediary microcontroller explained in detail, as well as the design of the needed circuit board.