How can i get printF to work in other .c files?

[iwagg]

I just started out a project with FreeRtos and followed this and managed to get it to work.

How to redirect the printf function to a UART for debug messages 

I can also printF from the freertos.c StartXXXTask functions.

But one of the start task functions i call my own method in my custom .C file i can't seem to printF from it. Within that function i can run this and it works, but not printF.

HAL_UART_Transmit(&huart2, buf, strlen((char*)buf), HAL_MAX_DELAY);

Wondering what am I doing wrong?

[Andrew Neil]

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@iwagg wrote:

 printF

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Why the uppercase 'F' - is this some custom "wrapper" for the standard printf ... ?

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@iwagg wrote:

But one of the start task functions i call my own method in my custom .C file i can't seem to printF from it.

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What do you mean by that? It doesn't build? You get no output? Other...?

[iwagg]

Apologies, that is my typo, it's not a custom wrapper.

It doesn't work as in no output. It compiles. Tried  putting a HAL uart transmit before and after the printf statement, those work and I get output, just no output from printf.

[Andrew Neil]

Does FreeRTOS have separate streams for each Task? Or require each Task to setup its own printf redirection?

If so, that would be a FreeRTOS question - not specific to STM32 ...

https://www.freertos.org/Documentation/RTOS_book.html

https://www.freertos.org/RTOS-contact-and-support.html

[iwagg]

I think I'm unable to answer that. I'm new to STM32, C and embedded. Only have background in web frontend JS. 

[Tesla DeLorean]

Likely you haven't got the plumbing setup properly via _write() and __io_putchar()

Could try

char buf[64];

HAL_UART_Transmit(&huart2, (void *)buf, sprintf(buf, "%d\n", 123), HAL_MAX_DELAY);

[iwagg · Accepted solution]

Not sure what I did, but it's working now.