AnsweredAssumed Answered

STM32F1 bootloader issue

Question asked by pavelm on Feb 13, 2015
Latest reply on Feb 13, 2015 by pavelm

in last batch from our supplier we have a problem with entering internal bootloader via USART1.
Something probably changed in the processors, because previously, there was absolutely no problem. Now we have lot of pieces from same batch, that are behaving strange.

We have found, that processor react correctly to BOOT0 pin, so it switching to bootloader, but it does not communicate via USART1 at all.
Strange is, that it works for some chips in 1/30 tries. Our PCB is very same for all the time, only part that can be problematic is most probably processor.
We have some pcs that there is corrupted FLASH memory too to the extent, that some part is working correctly, some pages can't save the data at all.

I am sure all is correctly soldered, we have changed processors to new, but they are from same batch so there is potentionally same problem.
If we enter finally the bootloader, then all is OK. Our firmware is working correctly.
Can you tell me, where can be a problem?

Bootloader is probably started, but it does not work (at least with USART).
We can see it clearly on the LED, even if there is our firmware and we want to activate internal bootloader, then LED is turned OFF which is correct, but bootloader does not respond.

Please help, as we are out of ideas.

Chip is STM32F103RBT6.