STM32 USART problem

I use STM32_Init.c file for configuration. It is standard configuration file from Keil MDK.

My aplication is very simple:

int main(void){

stm32_Init(); /* In this file I make usart configuration */

while (1);
}

After execute firs line of the code, I receive this sign "ü".

I use STM32_Init.c file for configuration. It is standard configuration file from Keil MDK.

My aplication is very simple:

int main(void){

stm32_Init(); /* In this file I make usart configuration */

while (1);
}

After execute firs line of the code, I receive this sign "ü".

Hello Mark Anders,

I can not explain what causes this extra character during UART initialisation but you can eleminate it if you add a little for-next loop before enabling the UART.

    for (i = 0; i < 800; i++);
    USART1->CR1 |= USART_CR1_UE;

Best Regards,
Martin Guenther

It is not at all unusual for any system to generate the odd "glitch" on startups - with a serial connection, that may well show up as an odd character...