usart receive

[soundarya_h_s]

USART receive is not providing the output please check and reply me asap

selected USART2 made it to asynchronous also enabled global interrupt
code lines that i have added

uint8_t txbuf[10]="hello ";

uint8_t rxbuf[10];

while (1)

{

/* USER CODE END WHILE */

HAL_UART_Receive(&huart2, rxbuf, sizeof(rxbuf), 100);

/* USER CODE BEGIN 3 */

}

void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)

{

HAL_UART_Transmit(&huart2, rxbuf, sizeof(rxbuf), 100);

}

[KDJEM.1]

Hello @soundarya_h_s ,

If you using the interrupt mode, the transmit and receive functions are HAL_UART_Transmit_IT() and HAL_UART_Receive_IT(). For that, I recommend you to take a look to this FAQ: How to use STM32 HAL UART driver API and Callbacks ?

Also, I think Getting started with UART can help you.

Thank you.

Kaouthar

[Karl Yamashita]

A better approach is to use the idle interrupt. That way you can receive any length string. You make your array size the longest string/bytes you'll expect. Then when you call HAL_UARTEx_ReceiveToIdle_IT, you pass an argument twice the size of your array. That way you'll either get an idle interrupt or if you're expecting like 5 bytes from "hello", it'll do a half callback interrupt. 

#define RX_BUFFER_SIZE 10
typedef struct
{
	int dataRdy;
	uint32_t size;
}RX_Status;
uint8_t rxbuf[RX_BUFFER_SIZE];

RX_Status rx_status = {0};


int main(void)
{
  HAL_UARTEx_ReceiveToIdle_IT(&huart2, rxbuf, RX_BUFFER_SIZE * 2);
  while (1)
  {
	  if(rx_status.dataRdy)
	  {
		  rx_status.dataRdy = 0;
		  HAL_UART_Transmit_IT(&huart2, rxbuf, rx_status.size);
	  }
  }
}

void HAL_UARTEx_RxEventCallback(UART_HandleTypeDef *huart, uint16_t Size)
{
	if(huart == &huart2)
	{
		rx_status.dataRdy = 1;
		rx_status.size = Size;
		HAL_UARTEx_ReceiveToIdle_IT(&huart2, rxbuf, RX_BUFFER_SIZE * 2);
	}
}

Make sure you enable UART interrupt

[soundarya_h_s]

@KDJEM.1 i tried disabling the global interrupt but i am not getting output

[Karl Yamashita]

HAL_UART_RxCpltCallback only works when interrupt is enabled. HAL_UART_Receive is only polling and will not trigger an interrupt callback. If you want polling then you have to rewrite your code to transmit what you received.

[soundarya_h_s]

#define ADC_BUF_SIZE 8

#define __VREFANALOG_VOLTAGE__ 3300

uint32_t ADC_buffer[ADC_BUF_SIZE];

uint8_t txbuf[30];

uint8_t adc_flag=0;

uint8_t led_flag=1;

uint8_t idx;

if(HAL_OK!=HAL_ADCEx_Calibration_Start(&hadc1, ADC_SINGLE_ENDED))

{

Error_Handler();

}

if(HAL_OK!=HAL_ADC_Start_DMA(&hadc1,ADC_buffer, ADC_BUF_SIZE))

Error_Handler();

if(HAL_OK!=HAL_TIM_Base_Start(&htim2))

Error_Handler();

HAL_UART_Transmit(&huart2,txbuf,1,0);

while (1)

{

if(led_flag==1)

{

HAL_GPIO_TogglePin(led_green_GPIO_Port, led_green_Pin);

HAL_Delay(500);

}

if(1==adc_flag)

{

for(idx=0;idx<ADC_BUF_SIZE;idx++)

{

ADC_buffer[idx]=__LL_ADC_CALC_TEMPERATURE(__VREFANALOG_VOLTAGE__,ADC_buffer[idx],LL_ADC_RESOLUTION_12B);

txbuf[0]=ADC_buffer[idx];

}

adc_flag=0;

}

/* USER CODE END WHILE */

/* USER CODE BEGIN 3 */

}

/* USER CODE END 3 */

}

void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef* hadc)

{

adc_flag=1;

}

void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin)

{

led_flag=!led_flag;

HAL_UART_Transmit(&huart2,txbuf,1, 0);

}

this is my code for blinking led for every one second on pressing user button led should stop bliking and also should send the ADC reading in the uart
but i cannot see the uart transmitted output on the window

[Karl Yamashita]

Use code sample so we can see formatted code to make it easier to read

int main(void)
{
	
#define ADC_BUF_SIZE 8
#define __VREFANALOG_VOLTAGE__ 3300
uint32_t ADC_buffer[ADC_BUF_SIZE];
uint8_t txbuf[30];
uint8_t adc_flag = 0;
uint8_t led_flag = 1;
uint8_t idx;

	if (HAL_OK != HAL_ADCEx_Calibration_Start(&hadc1, ADC_SINGLE_ENDED))

	{

		Error_Handler();

	}

	if (HAL_OK != HAL_ADC_Start_DMA(&hadc1, ADC_buffer, ADC_BUF_SIZE))
		Error_Handler();

	if (HAL_OK != HAL_TIM_Base_Start(&htim2))
		Error_Handler();

	HAL_UART_Transmit(&huart2, txbuf, 1, 0);

	while (1)
	{
		if (led_flag == 1)
		{
			HAL_GPIO_TogglePin(led_green_GPIO_Port, led_green_Pin);
			HAL_Delay(500);
		}

		if (1 == adc_flag)
		{
			for (idx = 0; idx < ADC_BUF_SIZE; idx++)
			{
				ADC_buffer[idx] = __LL_ADC_CALC_TEMPERATURE(
						__VREFANALOG_VOLTAGE__, ADC_buffer[idx],
						LL_ADC_RESOLUTION_12B);
				txbuf[0] = ADC_buffer[idx];
			}
			adc_flag = 0;
		}
		/* USER CODE END WHILE */

		/* USER CODE BEGIN 3 */
	}
	/* USER CODE END 3 */
}

void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef *hadc)
{
	adc_flag = 1;
}

void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin)
{
	led_flag = !led_flag;
	HAL_UART_Transmit(&huart2, txbuf, 1, 0);
}

Did you enable NVIC interrupt for the GPIO?

[Piranha]

Those zero timeouts for the HAL_UART_Transmit() calls are especially cool...

[Tesla DeLorean]

Making my head spin, things that need to be global and volatile.

Cramming data into a single byte, that might go out on an EXTI

Pulling data from an active DMA buffer.

Lot of disconnected code, ideas and concepts here.

[soundarya_h_s]

@Karl Yamashita 
yes i have enabled the NVIC interrupt for GPIO
also i am getting output for every other thing but not for uart