2024-09-27 6:40 AM - last edited on 2024-10-25 9:14 AM by mƎALLEm
Hello, I am a developer and I am using the L431RC chip on a custom board. I am using CAN BUS to communicate with the system, and during normal operation (via firmware), there are no communication issues,in fact, everything works quite well.
However, I encountered a major issue when trying to access the bootloader via CAN BUS. Essentially, I have run countless tests, but I never receive any response from the bootloader, and I don’t know why.
I should mention that I have followed the AN2606 and AN3154 documents to interface correctly, I am using the correct pins (PB8 and PB9), a 16MHz HSE, and TIM16 active as described in the files. To enter the bootloader, I use two external buttons, Reset and Boot.
The thing is, I tried accessing the bootloader via UART, and everything works, so the boot circuitry is functioning.
I have two STLINK V3 programmers, a SET and a MOD, but neither receives a response; I even tried connecting directly to the CAN's RX and TX (using the appropriate port) via the SET, but still nothing.
I also tried all of this on an F407, and everything works perfectly there.
Looking at the oscilloscope, I noticed that the L431 does not respond after sending 0x079, there is no ACK code, as if the chip was not enabled for CAN. Does anyone have any idea?
Solved! Go to Solution.
2024-10-25 9:05 AM
Hello @Fede ,
You need first to check your HW, transceiver etc ..then refer to this article as it may help: https://community.st.com/t5/stm32-mcus/how-to-connect-to-the-stm32-can-bootloader-interface/ta-p/49283
2024-10-25 9:05 AM
Hello @Fede ,
You need first to check your HW, transceiver etc ..then refer to this article as it may help: https://community.st.com/t5/stm32-mcus/how-to-connect-to-the-stm32-can-bootloader-interface/ta-p/49283