After Enabling FreeRTOS USART Baudrate Drops Down

[ÖSahi.1]

I'm trying to learn RTOS on STM32F407VG(Discovery Board). I am able to use the USART without FreeRTOS at 115200 baud rate. Nevertheless, when I enable FreeRTOS and try to send basic strings with the same USART settings(115200 baud rate etc.), I can not see the proper message from Hercules, HyperTerminal, or Serial Port Monitor at 115200 baud rate. But if I change the baud rate to 38400, I can see. It's not working at other baud rates instead of 115200. Am I missing something about the settings of RTOS?

[Andrew Neil]

"Am I missing something about the settings of RTOS?"

That's something that you'd have to ask the FreeRTOS people:

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

https://www.freertos.org/community/overview.html

https://www.freertos.org/a00104.html#getting-started

Remember that FreeRTOS is an independent 3rd-party product - nothing to do with ST or STM32.

"if I change the baud rate to 38400, I can see"

You mean the baud rate of the terminal here?

Sounds like your FreeRTOS system is running at 1/3 the rate of your non-FreeRTOS system?

[ÖSahi.1]

"You mean the baud rate of the terminal here?"

Yes.

"Sounds like your FreeRTOS system is running at 1/3 the rate of your non-FreeRTOS system?"

Yes. Let's make it clear.

Transmitter is Discovery Board and Receiver is PC.

Transmitter settings are at 115200 baudrate, PC settings are at 38400 baudrate.

[Andrew Neil]

"Transmitter settings are at 115200 baudrate"

So those setting will be correct for your non-FreeRTOS system clock.

If your FreeRTOS system clock is different, then your UART settings will need a corresponding change