UART only receive one byte

[MÇETİ.1]

I'm trying to receive more than 1 byte but it receive only 1 byte. Poll method or IT, it doesn't matter. Always receives 1 byte and writes it in rx_buffer[0]. When I search it I found out the reason is timeout, I increase timeout 1000 from 100ms but nothing changes. Can anyone help me please? 

Here is my code for poll

/* Includes ------------------------------------------------------------------*/

#include "main.h"

#include "string.h"

/* Private variables ---------------------------------------------------------*/

UART_HandleTypeDef huart1;

UART_HandleTypeDef huart6;

DMA_HandleTypeDef hdma_usart1_rx;

/* Private function prototypes -----------------------------------------------*/

void SystemClock_Config(void);

static void MX_GPIO_Init(void);

static void MX_DMA_Init(void);

static void MX_USART1_UART_Init(void);

static void MX_USART6_UART_Init(void);

USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/

/* USER CODE BEGIN 0 */

char rx_buffer[50];

char tx_buffer[50];

 while (1)

 {

HAL_UART_Receive(&huart1,(uint8_t*)rx_buffer,4,1000);

memcpy(tx_buffer,rx_buffer,4);

HAL_UART_Transmit(&huart6,(uint8_t*)tx_buffer,strlen(tx_buffer),1000);

  /* USER CODE END WHILE */

  /* USER CODE BEGIN 3 */

 }

[MÇETİ.1]

/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "string.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
 
/* USER CODE END Includes */
 
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
 
/* USER CODE END PTD */
 
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD */
 
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
 
/* USER CODE END PM */
 
/* Private variables ---------------------------------------------------------*/
UART_HandleTypeDef huart1;
UART_HandleTypeDef huart6;
DMA_HandleTypeDef hdma_usart1_rx;
DMA_HandleTypeDef hdma_usart6_tx;
 
/* USER CODE BEGIN PV */
 
/* USER CODE END PV */
 
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_DMA_Init(void);
static void MX_USART1_UART_Init(void);
static void MX_USART6_UART_Init(void);
/* USER CODE BEGIN PFP */
 
/* USER CODE END PFP */
 
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
#define rx_buff 512
#define main_buff 2048
 
uint8_t rx_buffer[rx_buff];
uint8_t main_buffer[main_buff];
 
uint16_t oldPos;
uint16_t newPos;
 
void HAL_UARTEx_RxEventCallback(UART_HandleTypeDef *huart, uint16_t Size)
{
	if (huart->Instance == USART1)
	{
		oldPos = newPos;  // Update the last position before copying new data
 
		if (oldPos+Size > main_buff)  // If the current position + new data size is greater than the main buffer
		{
			uint16_t datatocopy = main_buff-oldPos;  // find out how much space is left in the main buffer
			memcpy ((uint8_t *)main_buffer+oldPos, rx_buffer, datatocopy);  // copy data in that remaining space
 
			oldPos = 0;  // point to the start of the buffer
			memcpy ((uint8_t *)main_buffer, (uint8_t *)rx_buffer+datatocopy, (Size-datatocopy));  // copy the remaining data
			newPos = (Size-datatocopy);  // update the position
		}
 
		/* if the current position + new data size is less than the main buffer
		 * we will simply copy the data into the buffer and update the position
		 */
		else
		{
			memcpy ((uint8_t *)main_buffer+oldPos, rx_buffer, Size);
			newPos = Size+oldPos;
		}
 
 
		/* start the DMA again */
		HAL_UARTEx_ReceiveToIdle_DMA(&huart1, (uint8_t *) rx_buffer, rx_buff);
		__HAL_DMA_DISABLE_IT(&hdma_usart1_rx, DMA_IT_HT);
		HAL_UART_Transmit_DMA(&huart6,rx_buffer, sizeof(rx_buffer));
	}
}
 
 
 
/* 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_DMA_Init();
  MX_USART1_UART_Init();
  MX_USART6_UART_Init();
  /* USER CODE BEGIN 2 */
HAL_UARTEx_ReceiveToIdle_DMA(&huart1, rx_buffer, rx_buff);
HAL_UART_Transmit_DMA(&huart6, rx_buffer, sizeof(rx_buffer));
  /* USER CODE END 2 */
 
  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
    /* USER CODE END WHILE */

[Karl Yamashita · Accepted solution]

From what i see, main_buffer is pointless as you are not doing anything with it.

My UART2 is your UART1 and my UART1 is your UART6 which this is working on a Nucleo-L432 board

uint8_t tx_buffer[rx_buff];
 
void HAL_UARTEx_RxEventCallback(UART_HandleTypeDef *huart, uint16_t Size)
{
	if (huart->Instance == USART2)
	{
	
		/* start the DMA again */
		memset(&tx_buffer, 0, sizeof(tx_buffer)); // clear tx buffer
		memcpy(&tx_buffer, &rx_buffer, Size); // copy only what was received
		
		HAL_UART_Transmit_DMA(&huart1, tx_buffer, Size); // use Size instead of sizeof(rx_buffer)
		
		HAL_UARTEx_ReceiveToIdle_DMA(&huart2, (uint8_t *) rx_buffer, sizeof(rx_buffer));
	}
}

[MÇETİ.1]

Thank you so much!!!! It works!!

[Karl Yamashita]

You're welcome! Can you please select as best answer?