The process of brushing CAN card program mainly involves three steps: pre-programming step, programming step and post-programming step. In the pre-programming step, it is mainly to wake up the ECU, read the specific DID, and manage the communication. Then comes the programming step, which uses the initial program boot of CAN bus to read the program file to be burned and store it in flash to complete the self-program update. Finally, there is the post-programming step, when the program update is complete, the device will restart.
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If the ECU software needs to be updated through the OBD port or the CAN bus, then the programming language is generally chosen CAPL. In addition, the UDS protocol based Bootloader software implementation is also a common solution. For example, some projects provide the use of QT (C) implementation of the upper computer interface program, and support STM32F1, STM32F2, STM32F4 series of microcontroller sample source code. In specific use, it is necessary to find the source code corresponding to the single chip computer used, open and check whether the CAN bus pin configuration matches with the corresponding software, if not the same, it is necessary to change the CAN bus pin configuration part of the code.