printf not working via ITM_Sendchar, _write never called

[hegde_08]

I am trying to use SWD for printing using ITM_Sendchar, Printf not calling _write, I tried to put breakpoint and see, But it is not hitting breakpoint

 

 

 

[KnarfB]

By default, stdout is line buffered. You will see output only after a newline '\n'. Less common: stdout buffering might be changed to unbuffered as well.

hth

KnarfB

[Andrew Neil]

welcome to the forum.

Please see How to write your question to maximize your chances to find a solution - particularly how to post source code (not as images).

See also: How to insert source code

 

As @KnarfB said, stdout defaults to line-buffered, so you won't see any output until a newline is sent.

This is also noted in the Knowledgebase article, How to redirect the printf function to a UART for debug messages.

See also: https://community.st.com/t5/stm32-mcus/how-to-redirect-the-printf-function-to-a-uart-for-debug-messages/ta-p/49865#:~:text=5.2.%20Line%2Dbuffering,has%20been%20formed - which includes how to disable the line-buffering.

Also Try: 

printf( "Hello World!\n" );

instead...

[hegde_08]

I just came here to give update, So _write is called, But now Even though I enabled SWD, and trace, and Port 0, Print is not working

 

[gbm]

Board type? (If ST.) Schematic? (If your own.)

[hegde_08]

STM32 , NUCLEO-F303RE

[Andrew Neil]

Is SB15 fitted?

https://www.st.com/resource/en/user_manual/um1724-stm32-nucleo64-boards-mb1136-stmicroelectronics.pdf#page=15

via: https://www.st.com/en/evaluation-tools/nucleo-f303re.html#documentation

[gbm]

Is the SWO pin configured in CubeMX?

[hegde_08]

How do I check this? any steps would be helpful

[hegde_08]

This is the board I got

[Andrew Neil]

So check to see if SB15 is open or closed

[hegde_08]

I am new to this, What exactly need to be checked in the board

 

[Tesla DeLorean]

Clock speed needs to match.

Doesn't the STM32F3 have a default HSI of 8 MHz?

Use that speed.

Perhaps also output to the VCP USART so you can see in a Terminal app, and print out SystemCoreClock to confirm.

[hegde_08]

I was trying not to use HAL Drivers, But surely I will try this once