Terrible Experience with STM32 UART HAL

[andy2399]

Posted on September 17, 2015 at 23:47

I am having no end of difficulty doing even the simplest thing with serial ports.

I am using STM32CubeMX to generate my project which is being compiled by CrossWorks. I try to send a string of text using: HAL_UART_Transmit( &huart3, ( uint8_t * )''TEST\r\n'', 6,0 ); All I get out the serial port is T nothing else ! I also wait for incoming characters using:  if ( HAL_UART_Receive( &huart3, buff, 1, 0 ) == HAL_OK ) but despite typing characters into the terminal application this function never returns HAL_OK. So I tried enabling interrupts on UART3 and used: HAL_UART_Transmit_IT( &huart3, ( uint8_t * )''TEST\r\n'', 6 ); Still nothing but if I trace the code through the ISR, it seems to be failing with HAL_BUSY Does anyone have any idea what I am doing wrong ? Andy #free-the-mallocs

[Tesla DeLorean]

Posted on September 18, 2015 at 02:15

Does anyone have any idea what I am doing wrong ?

We'll be here when you decide it's the HAL

[Barber.Mark]

Posted on September 18, 2015 at 03:11 Hi Andy, timeout value needs to be greater than 0. try 200. HAL_UART_Transmit( &huart3, ( uint8_t * )''TEST\r\n'', 6,200 ); Mark

[andy2399]

Posted on September 18, 2015 at 23:42

Mark,

Thanks for your help. I tried as you suggested and got ''TEST'' however, if I change the line to HAL_UART_Transmit( &huart3, ( uint8_t * )''TESTING1234\r\n'', 15,200 ); I only get ''TESTING12'' ! Clive, Not sure what your comment is supposed to mean ! Are you suggesting that I am wrong thinking the issue is with the HAL ? Andy

[andy2399]

Posted on September 18, 2015 at 23:48

In further testing, I decided to debug the firmware and see what code was returned from HAL_UART_Transmit and so set a breakpoint on the line following Transmit and it never breaks as it gets a hard fault. The stack trace showed the hard fault occured in

UART_WaitOnFlagUntilTimeout. Andy

[andy2399]

Posted on September 20, 2015 at 21:47

Looks like my issue was stack size now my UART transmit and receive appear to be working :)

[billmeteor]

Posted on October 02, 2015 at 09:52

Hi Andy,

Can you explain the problem about stack size?I seem to have the same issue.Bill