STM32 Uart Overrun

[yairyamin]

Hello every one .

this is my first post so excuse me if i do something wrong.

I try to establish Uart Asynchronous line between two stm32f303k8 .one of them use basic timer to send 8 byte uint buffer every 200 mili-sec and the other use HAL_UART_Receive_IT first in the "/* USER CODE BEGIN 2 */"

and circularly recall it again in HAL_UART_RxCpltCallback.

So my problem is that after the first reception i get overrun error and when i enable overrun in the CubeMX i see that after the first reception the first byte are the last byte of the previous message and all other bytes are shifted right .

**I attached image of   my  UART configuration (same for both of them)

Sender variables :

uint8_t m_tx_buffer[8] = {0};
uint8_t flag = 0;

 Sender while(1): 

    if (flag == 1)
    {
        flag = 0;
        HAL_UART_Transmit_IT(&huart1, m_tx_buffer, sizeof(m_tx_buffer));
        m_tx_buffer[5] ++;
    }

Receiver variables : 

volatile  uint8_t s_rx_buffer[8] = {0};
uint8_t s_tx_buffer[8] = {0};
uint8_t flag = 0;

Receiver Callback :

void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
  while(HAL_UART_GetState(huart) == HAL_UART_STATE_BUSY);
  memset(s_rx_buffer, 0, sizeof(s_rx_buffer));
  HAL_UART_Receive_IT(huart, s_rx_buffer, sizeof(s_rx_buffer));
}

I basically try everything, and it is not working. I try to move to DMA and i try to change the word length of the Uart I try to use slowing the sending of messages and try to see other's post on the internet. and i really not understanding how to fix that.

---

Source code formatting applied

[Andrew Neil]

---

@unsigned_char_array wrote:
I wrote about this before:

---

Indeed - it is a very commonly recurring theme!

[yairyamin · Accepted solution]

thanks a lot i decide to change the Uart-rx to circular mode and the Tx remain in normal mode and it is fix the problem!!

[Andrew Neil]

Excellent - so please mark the solution:

https://community.st.com/t5/community-guidelines/help-others-to-solve-their-issues/ta-p/575256