UART communication problem

[bakhti]

hi i'm trying to use the stm32H750 uart with Interrupt i managed to get it working but the message is a bit off ( alot ) here is a bit of the code

uint8_t tx_buff[]="                                                                      ";
uint8_t rx_buff[20];

  HAL_UART_Receive_IT(&huart1, &rx_buff[0], 20);

void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart){
n3=n3+5;
HAL_UART_Receive_IT(huart, &rx_buff[0], 20);
check = rx_buff[0];
if (check==67){
	n1=n1+100;
};
HAL_UART_Transmit_IT(&huart1, rx_buff, 21);
 
}

what i'm doing to try it , is that i'm monitoring via stmstudio and whenever a message arrive i'll rederect to the the host and read it again

here are the results

rx is coming back from mcu

[TDK]

Seems like the clock is off. Check your clock settings including HSITRIM which CubeMX has a history of getting incorrect. Could also be that you're using incompatible UART settings.

[Tesla DeLorean]

Baud rates probably off, get a scope, check the timings and settings you're pushing in.

Does a simple one-at-a-time polling method work? How about sending?

Why does the transmit send 21 characters?

I'd probably copy the rx_buff to tx_buff before recommitting the rx_buff

H7 doesn't output at RS232 levels

[bakhti]

-baudrate is set on 9600 on both the emitter(pc) receiver(stm32)

-reading one time is not working either

 while (1)
  {
    /* USER CODE END WHILE */
 
    /* USER CODE BEGIN 3 */
	  HAL_UART_Receive(&huart1, rx_buff, sizeof(rx_buff), HAL_MAX_DELAY);
	  HAL_Delay(500);
	  HAL_UART_Transmit(&huart1, rx_buff, sizeof(rx_buff), HAL_MAX_DELAY);
	  HAL_Delay(500);
  }

-just for testing i had a problem where the receive function didn't start from the 0

[bakhti]

where does one find that

[TDK]

In RCC_OscInitStruct.HSICalibrationValue.

[Tesla DeLorean]

Prove that the output works, if that doesn't function there is no hope for reception.

while (1)

{

 char str[] = "UUUUU testing *****\r\n";

 HAL_UART_Transmit(&huart1, str, sizeof(str)-1, HAL_MAX_DELAY);

 HAL_Delay(500);

}

I suspect the UART connectivity is broken, but would need to understand schematic/connectivity you have wired.

[bakhti]

[bakhti]

  RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;

what should i change it to

[bakhti]

works too with arduino serial