STM32F1 USART problem

[markus-muc]

Posted on February 17, 2016 at 18:38

Hi, I am new to the STM32 family and I am stuck with a pretty basic problem. 

My board (STM32F105 CAN study board) came with a basic software in Flash, and I got the sources of that software which I am running from RAM. However, the USART2 does not behave the same from the source code in RAM. I.e., the code should output on USART2:++++++++++++++++++++++++  CAN Study Board++++++++++++++++++++++++But when I run the program 3 times in the following sequence:1. From Flash2. From RAM3. From Flash (again)the Putty output looks like this:++++++++++++++++++++++++  CAN Study Board++++++++++++++++++++++++▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒++++++++++++++++++++++++  CAN Study Board++++++++++++++++++++++++So the characters from the RAM implementation are corrupt. Any idea what the problem could be?

[Tesla DeLorean]

Posted on February 17, 2016 at 18:44

Any idea what the problem could be?

Your RAM based code is built with the wrong HSE_VALUE defined?HSE_VALUE needs to match the speed of the crystal used in your design.

[markus-muc]

Posted on February 17, 2016 at 18:58

YESSS! 

Thanks for the extremely quick response, that was it!