USART bootloader on STM303x

[gbigden]

Posted on March 17, 2016 at 16:43

According to section 19 of AN2606 if I want to use USART2 I have to go through pins PA2, PA3 - is this correct.

Anyway, I connect to these via an FTDI USB/USART i/f chip. Bottom line is that I cannot get the STM Flashloader Demo to connect.Any advice on what's happening? #stm32f303x #stm32-bootloader #worst-forum-software-ever

[Tesla DeLorean]

Posted on March 17, 2016 at 19:12

Which exact part# are we talking about, there are F3 devices with USART2 on PA2/PA3 and others on PD5/PD6

Set the Demo aside for a second, and use something like RealTerm where you can send/receive HEX bytes.With the port configured in 9600 8E1 (Even), send an 0x7F character, and observe if you get an 0x79 response. If that works, sends some other commands like 0x00,0xFF and 0x01,0xFEThe auto-baud is a one-shot deal, you need to reset and startup over if that gets messed up. Make sure BOOT0 is pulled high. Try other USART and USB also if possible.

[gbigden]

Posted on March 18, 2016 at 09:50

Hi - The part is STM32F303VCT6

Cannot get any response using RealTerm

[Tesla DeLorean]

Posted on March 18, 2016 at 12:39

And the chip is otherwise functional, and you can connect to it with SWD or JTAG, and you've checked the USART functionality and connectivity with your own code?

If the device is non-responsive, what is the state of the NRST pin?

[gbigden]

Posted on March 18, 2016 at 13:13

Hi - yes. The USART is connected through a FT230X USB i/f. The whole board is running correctly and I routinely connect via the FT USB i/f at 230kBaud and higher.

NRST is normally pulled Hi through a 100K resistor in the CR reset circuit

[Tesla DeLorean]

Posted on March 18, 2016 at 14:09

Table 34 indicates your part (303xC) uses PD5/6 for the USART2 connectivity to the system loader.

http://www.st.com/web/en/resource/technical/document/application_note/CD00167594.pdf

[gbigden]

Posted on March 18, 2016 at 15:52

OK - On the STM32F303VCT6 it is not obvious that the part is ''C'' and not (say) ''6'' as in Table 38

Anyway, we can do without a bootloader so it's not a problem