System Bootloader not working but UART1 works OK.

bob239955 · ‎2009-01-15

Posted on January 15, 2009 at 14:22

matt1 · ‎2011-05-17

Posted on May 17, 2011 at 12:19

Hi all,

I seem to be having a similar problems to those described here.

My RS232 transceiver was outputting garbage on the RS232 side until I added a pull-down to the TTL side. This seems to have resolved the problems with the bootloader.

Is the Tx pin from the STM floating when in system bootloader mode until data is received on the Rx pin? This would seem strange.. but I can't see any other reason why the changes I made resolved the problem.

Matt

adrian3 · ‎2011-05-17

Posted on May 17, 2011 at 12:19

I'm just wondering - should Boot 1 be connected directly to ground as it doubles as Port B-2? What happens if you remove the pull up resistor R48, and connect to ground via a suitable resistor?

bob239955 · ‎2011-05-17

Posted on May 17, 2011 at 12:19

Thanks Adrian,STOne-32

RESOLVED - PARTIALLY as follows, but there are some questions...

Using another PC (a Laptop) the program worked at 9600 and 19200 baud only.

However my own STM32 USART1 application works with all COM ports on all PC's that I tried -- and at 115200 baud - exactly the same hardware.

I had been hoping it would be possible to use 115200 baud with the Flash Loader Demonstrator 1.0. Has anyone got the Flash Loader Demonstrator 1.0 working at 115200 baud?.

When the Flash Loader Demonstrator works, it seems to work with ANY Parity setting, and 8 data bits, what setting should I use? or does it ignore parity?

Removing R48 and using a pulldown made no difference, but it was a welcome suggestion - thanks Adrian.

Thanks.

[ This message was edited by: bobz on 14-12-2007 12:25 ]

[ This message was edited by: bobz on 14-12-2007 13:20 ]

[ This message was edited by: bobz on 14-12-2007 13:32 ]

bsy006 · ‎2011-05-17

Posted on May 17, 2011 at 12:19

Hello, I see the Flash Loader Demonstrator 1.2 (not 1.0) works OK @ 115.2k

STM' BootLoader is v2.0.

Yuri.