STM32F4 Problem receiving data from uart with interrupt

Question

I've problems receiving data from uart2 with interrupt. I'm using ST32F411VET and for test I've created a specific project with CubeMX. I've connected USB FTDI converter from my PC to STM Board. In polling mode I can send and receive data, but some bytes are lost. Moreover, blocking mode is not good for me. Then I decided to use Interrupt mode, but I can send data from STM to PC, but don't receive any byte from PC. This is the code: main.c

#include "main.h"

__root uint16_t i; 
uint8_t rx_buffer[256];

UART_HandleTypeDef huart2;

void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART2_UART_Init(void);

int main(void)
{
  HAL_Init();
  SystemClock_Config();
  MX_GPIO_Init();
  MX_USART2_UART_Init();

  HAL_UART_Transmit(&huart2, (uint8_t*)"Ready...\r\n", 10, 100);
  HAL_UART_Receive_IT(&huart2, (uint8_t *)rx_buffer, 4);

  while (1) {}
}

void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
  HAL_UART_Receive_IT(&huart2, (uint8_t *)rx_buffer, 4);
  i++;
}



void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  __HAL_RCC_PWR_CLK_ENABLE();
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);

  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }

  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                              |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
  {
    Error_Handler();
  }
}

static void MX_USART2_UART_Init(void)
{
  huart2.Instance = USART2;
  huart2.Init.BaudRate = 115200;
  huart2.Init.WordLength = UART_WORDLENGTH_8B;
  huart2.Init.StopBits = UART_STOPBITS_1;
  huart2.Init.Parity = UART_PARITY_NONE;
  huart2.Init.Mode = UART_MODE_TX_RX;
  huart2.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart2.Init.OverSampling = UART_OVERSAMPLING_16;
  if (HAL_UART_Init(&huart2) != HAL_OK)
  {
    Error_Handler();
  }
}

static void MX_GPIO_Init(void)
{
  __HAL_RCC_GPIOD_CLK_ENABLE();
}

void Error_Handler(void)
{
}

#ifdef  USE_FULL_ASSERT
void assert_failed(uint8_t *file, uint32_t line)
{ 
}
#endif /* USE_FULL_ASSERT */

and GPio is set to stm32f4xx_hal_msp.c

void HAL_UART_MspInit(UART_HandleTypeDef* huart)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};
  if(huart->Instance==USART2)
  {
    __HAL_RCC_USART2_CLK_ENABLE();
    __HAL_RCC_GPIOD_CLK_ENABLE();
    PD5     ------> USART2_TX
    PD6     ------> USART2_RX 

    GPIO_InitStruct.Pin = GPIO_PIN_5|GPIO_PIN_6;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
    GPIO_InitStruct.Alternate = GPIO_AF7_USART2;
    HAL_GPIO_Init(GPIOD, &GPIO_InitStruct);

    HAL_NVIC_SetPriority(USART2_IRQn, 0, 0);
    HAL_NVIC_EnableIRQ(USART2_IRQn);
  }
}

I've searched for solution, but without luck. Can you help me? Thanks.

Answer 1

Why do you have an appointment buffer that costs 4?

HAL_UART_Receive_IT(&huart2, (uint8_t *)rx_buffer, 4);

Try taking one character at a time and analyzing them and adding them to an array.

HAL_UART_Receive_IT(&huart2, (uint8_t *)rx_buffer, 1);

And try this example

  uint8_t rx_data = 0;
    uint8_t rx_buffer[256];
    int rx_index = 0;

    HAL_UART_Receive_IT(&huart2, &rx_data, 1);

    void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart) {
     if (huart == &huart2) {
        if (rx_buffer != '\n'){
                rx_buffer[rx_index++] = rx_data;
        }else{
                YouFun((char *) rx_buffer);
                rx_index = 0;
                memset(rx_buffer, 0, sizeof(rx_buffer));
        }
        HAL_UART_Receive_IT(&huart2, &rx_data, 1);     // activate receive
     }
    }