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HAL_UART_Receive_IT() only fires once, and I don't know why.

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BBara.1
Associate II

‎2023-02-27 11:49 PM

Hi!

I am trying to write a program where I am waiting for receiving 6 bytes of data through UART. It works just fine the first time, than I restart the receive_IT function and nothing happens anymore. I have other codes where I use it just the same, the only difference is the MCU. For this project I am using an STM32F030F4P6.

main.c 

volatile uint8_t rx_buffer[6] = {0};
int8_t step = 1;
/* USER CODE END 0 */
 
/**
  * @brief  The application entry point.
  * @retval int
  */
int main(void)
{
  /* USER CODE BEGIN 1 */
 
  /* USER CODE END 1 */
 
  /* MCU Configuration--------------------------------------------------------*/
 
  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();
 
  /* USER CODE BEGIN Init */
 
  /* USER CODE END Init */
 
  /* Configure the system clock */
  SystemClock_Config();
 
  /* USER CODE BEGIN SysInit */
 
  /* USER CODE END SysInit */
 
  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_TIM3_Init();
  MX_USART1_UART_Init();
  MX_TIM14_Init();
  /* USER CODE BEGIN 2 */
  HAL_UART_Receive_IT(&huart1, rx_buffer, 6);
 
  HAL_GPIO_WritePin(Sleep_X_GPIO_Port, Sleep_X_Pin, GPIO_PIN_SET);
  HAL_GPIO_WritePin(Sleep_Y_GPIO_Port, Sleep_Y_Pin, GPIO_PIN_SET);
  HAL_GPIO_WritePin(Sleep_Z_GPIO_Port, Sleep_Z_Pin, GPIO_PIN_SET);
  HAL_GPIO_WritePin(Step_X_GPIO_Port, Step_X_Pin, GPIO_PIN_RESET);
  HAL_GPIO_WritePin(Step_Y_GPIO_Port, Step_Y_Pin, GPIO_PIN_RESET);
  HAL_GPIO_WritePin(Step_Z_GPIO_Port, Step_Z_Pin, GPIO_PIN_RESET);
  HAL_GPIO_WritePin(Dir_GPIO_Port, Dir_Pin, GPIO_PIN_RESET);
 
 
  /* USER CODE END 2 */
 
  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
    /* USER CODE END WHILE */
 
    /* USER CODE BEGIN 3 */
  }
  /* USER CODE END 3 */
}

stm32f0xx_it.c

void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart){
	/*
	 * x, e = 221
	 * x, h = 224
	 *
	 * y, e = 222
	 * y, h = 225
	 *
	 * z, e = 223
	 * z, h = 226
	 *
	 * p, k = 219
	 * p, b = 210
	 */
 
	for(i=0; i<2; i++){
		sum_rx += rx_buffer[i];
	}
 
	for(i=2;i<6;i++){
		sum_step += ((rx_buffer[i] - 48) * power(10, 5-i));
	}
 
	/*sum_step += (rx_buffer[5] - 48);
	sum_step += ((rx_buffer[4] - 48) * 10);
	sum_step += ((rx_buffer[3] - 48) * 100);
	sum_step += ((rx_buffer[2] - 48) * 1000);*/
 
	switch(sum_rx){
 
	case 221:
		HAL_GPIO_WritePin(Dir_GPIO_Port, Dir_Pin, GPIO_PIN_RESET);
		HAL_GPIO_WritePin(Sleep_X_GPIO_Port, Sleep_X_Pin, GPIO_PIN_SET);
		for(i=0; i<sum_step; i++){
			HAL_GPIO_WritePin(Step_X_GPIO_Port, Step_X_Pin, GPIO_PIN_SET);
			Delay(2);
			HAL_GPIO_WritePin(Step_X_GPIO_Port, Step_X_Pin, GPIO_PIN_RESET);
		}
		HAL_GPIO_WritePin(Sleep_X_GPIO_Port, Sleep_X_Pin, GPIO_PIN_RESET);
	break;
	case 224:
		HAL_GPIO_WritePin(Dir_GPIO_Port, Dir_Pin, GPIO_PIN_SET);
		HAL_GPIO_WritePin(Sleep_X_GPIO_Port, Sleep_X_Pin, GPIO_PIN_SET);
		for(i=0; i<sum_step; i++){
			HAL_GPIO_WritePin(Step_X_GPIO_Port, Step_X_Pin, GPIO_PIN_SET);
			Delay(2);
			HAL_GPIO_WritePin(Step_X_GPIO_Port, Step_X_Pin, GPIO_PIN_RESET);
		}
		HAL_GPIO_WritePin(Sleep_X_GPIO_Port, Sleep_X_Pin, GPIO_PIN_RESET);
	break;
 
 
 
	case 222:
		HAL_GPIO_WritePin(Dir_GPIO_Port, Dir_Pin, GPIO_PIN_RESET);
		HAL_GPIO_WritePin(Sleep_Y_GPIO_Port, Sleep_Y_Pin, GPIO_PIN_SET);
		for(i=0; i<sum_step; i++){
			HAL_GPIO_WritePin(Step_Y_GPIO_Port, Step_Y_Pin, GPIO_PIN_SET);
			Delay(2);
			HAL_GPIO_WritePin(Step_Y_GPIO_Port, Step_Y_Pin, GPIO_PIN_RESET);
		}
		HAL_GPIO_WritePin(Sleep_Y_GPIO_Port, Sleep_Y_Pin, GPIO_PIN_RESET);
	break;
	case 225:
		HAL_GPIO_WritePin(Dir_GPIO_Port, Dir_Pin, GPIO_PIN_SET);
		HAL_GPIO_WritePin(Sleep_Y_GPIO_Port, Sleep_Y_Pin, GPIO_PIN_SET);
		for(i=0; i<sum_step; i++){
			HAL_GPIO_WritePin(Step_Y_GPIO_Port, Step_Y_Pin, GPIO_PIN_SET);
			Delay(2);
			HAL_GPIO_WritePin(Step_Y_GPIO_Port, Step_Y_Pin, GPIO_PIN_RESET);
		}
		HAL_GPIO_WritePin(Sleep_Y_GPIO_Port, Sleep_Y_Pin, GPIO_PIN_RESET);
	break;
 
 
 
	case 223:
		HAL_GPIO_WritePin(Dir_GPIO_Port, Dir_Pin, GPIO_PIN_RESET);
		HAL_GPIO_WritePin(Sleep_Z_GPIO_Port, Sleep_Z_Pin, GPIO_PIN_SET);
		for(i=0; i<sum_step; i++){
			HAL_GPIO_WritePin(Step_Z_GPIO_Port, Step_Z_Pin, GPIO_PIN_SET);
			Delay(2);
			HAL_GPIO_WritePin(Step_Z_GPIO_Port, Step_Z_Pin, GPIO_PIN_RESET);
		}
		HAL_GPIO_WritePin(Sleep_Z_GPIO_Port, Sleep_Z_Pin, GPIO_PIN_RESET);
	break;
	case 226:
		HAL_GPIO_WritePin(Dir_GPIO_Port, Dir_Pin, GPIO_PIN_SET);
		HAL_GPIO_WritePin(Sleep_Z_GPIO_Port, Sleep_Z_Pin, GPIO_PIN_SET);
		for(i=0; i<sum_step; i++){
			HAL_GPIO_WritePin(Step_Z_GPIO_Port, Step_Z_Pin, GPIO_PIN_SET);
			Delay(2);
			HAL_GPIO_WritePin(Step_Z_GPIO_Port, Step_Z_Pin, GPIO_PIN_RESET);
		}
		HAL_GPIO_WritePin(Sleep_Z_GPIO_Port, Sleep_Z_Pin, GPIO_PIN_RESET);
	break;
 
	case 219:
		htim3.Instance -> CCR1 = ki;
		HAL_TIM_PWM_Start(&htim3, TIM_CHANNEL_1);
		Delay(150);
		HAL_TIM_PWM_Stop(&htim3, TIM_CHANNEL_1);
	break;
 
	case 210:
		htim3.Instance -> CCR1 = be;
		HAL_TIM_PWM_Start(&htim3, TIM_CHANNEL_1);
		Delay(150);
		HAL_TIM_PWM_Stop(&htim3, TIM_CHANNEL_1);
	break;
	default:
	break;
	}
 
	for(i=0; i<7; i++){
		rx_buffer[i] = 0;
	}
 
	HAL_UART_Receive_IT(huart, rx_buffer, 6);
 
	step = 1;
 
	sum_rx = 0;
	sum_step = 0;
}
 
void Delay(uint8_t ms){
	HAL_TIM_Base_Start(&htim14);
	while(htim14.Instance -> CNT < ms){
 
	}
	htim14.Instance -> CNT = 0;
	HAL_TIM_Base_Stop(&htim14);
}
 
int power(int x, int y){
	int i;
	int eredm = x;
	if(y != 0){
		for(i=1; i<y; i++){
			eredm *= x;
		}
	}
	else
		eredm = 1;
	return eredm;
}

I also tried not to call the HAL_UART_Receive_IT() inside the callback function, nothing else happened. I also checked the UART registers and everything seems the same as when I call the function the first time.

Thank you in advance!

********

Edit:

Thank you for the answers but today I was able to find the solution, yet I still don’t know why.

So Inoticed that the EIE bit in CR3 register don’t set to 1 after the second call of the HAL_UART_Receive_IT() function, but if I set it to 1 by hand before the function it works just fine.

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11 REPLIES 11
Go to solution
BBara.1
Associate II

‎2023-03-03 06:43 AM

Thank you for the answers but today I was able to find the solution, yet I still don’t understand.

So Inoticed that the EIE bit in CR3 register don’t set to 1 after the second call of the HAL_UART_Receive_IT() function, but if I set it to 1 by hand before the function it works just fine.

Go to solution
shane mattner
Senior
In response to BBara.1

‎2023-08-15 06:44 AM

Thank you @BBara.1 ,  I'm running into this same weird issue and calling MX_USART1_UART_Init() worked for allowing more interrupt reads.

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