Only receive one byte of string in UART

[AKhot.1]

I am not able to receive the full string in the RDR resgister. eg. If I am transmitting "hello" I am receiving only "h".

How to get a full string? Can anyone please help?

uint8_t Temp;

 while( !( USART2->ISR & USART_ISR_RXNE ) ) {

  Temp = USART2->RDR;

  HAL_GPIO_WritePin(LD2_GPIO_Port, LD2_Pin, GPIO_PIN_RESET);

 };

[AKhot.1]

I even tried the interrupt and the DMA approach but I am not getting it is still not working. I running the code in debug mode to analyze everything. I am giving input from hercules software. But nothing is working. The RxBuffer is showing 0 only. Can anyone please help

HAL_UART_Receive_DMA(&huart2,RxBuffer,3);
__HAL_UART_ENABLE_IT(&huart2, UART_IT_IDLE);
HAL_GPIO_WritePin(LD2_GPIO_Port, LD2_Pin, GPIO_PIN_RESET);

void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart){

HAL_UART_Receive_DMA(&huart2,RxBuffer,3);

}

void USART2_IRQHandler(void)

{

  /* USER CODE BEGIN USART2_IRQn 0 */

if(__HAL_UART_GET_FLAG(&huart2,UART_FLAG_IDLE))

{

HAL_UART_DMAStop(&huart2);

//Calculate the length of the received data

RxLength= 3 - __HAL_DMA_GET_COUNTER(&hdma_usart2_rx);

//Restart to start DMA transmission of 255 bytes of data at a time

HAL_UART_Receive_DMA(&huart2, (uint8_t*)RxBuffer, 3);

}

  /* USER CODE END USART2_IRQn 0 */

  HAL_UART_IRQHandler(&huart2);

  /* USER CODE BEGIN USART2_IRQn 1 */

  /* USER CODE END USART2_IRQn 1 */

}

[waclawek.jan · Accepted solution]

> I running the code in debug mode to analyze everything.

Don't observe UART registers using debugger while it's running.

JW

[AKhot.1]

You are right, debug mode made problems to the register or even say HAL_Receive_IT/HAL_Receive_DMA functions.