So, I'm having strange behavior regarding the serial number of my board with an STM32F091.
I have a Python software that sends a packet on the serial port every 100 ms. I have initialized the serial port on the ucontroller with the same settings as are set in the Python software to transmit.
/* USART2 init function */
static void MX_USART2_UART_Init(void)
{
huart2.Instance = USART2;
huart2.Init.BaudRate = 38400;
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;
huart2.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
huart2.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
if (HAL_UART_Init(&huart2) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
HAL_UART_Receive_IT(&huart2, &cdr2, 1);
}
I'm using the RX callback to manage the RX on the serial port
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *UartHandle)
{
/* Set transmission flag: trasfer complete*/
if (UartHandle->Instance == USART2)
{
rx2[puwrrx2] = cdr2;
if( puwrrx2 < ( RX2_LEN - 1 ) )
puwrrx2++;
else
puwrrx2 = 0;
HAL_UART_Receive_IT(&huart2, &cdr2, 1);
}
}
and the TX callback to put back the serial in RX
void HAL_UART_TxCpltCallback(UART_HandleTypeDef *UartHandle)
{
/* Set transmission flag: trasfer complete*/
if (UartHandle->Instance == USART2)
DE_RS485_LOW;
}
with
#define DE_RS485_HIGH HAL_GPIO_WritePin(RS485_En2_uC_GPIO_Port, RS485_En2_uC_Pin, GPIO_PIN_SET)
#define DE_RS485_LOW HAL_GPIO_WritePin(RS485_En2_uC_GPIO_Port, RS485_En2_uC_Pin, GPIO_PIN_RESET)
I trasmit every 100 ms with a function that calls
DE_RS485_HIGH;
HAL_UART_Transmit_IT(&huart2, tx2, packet_lenght);
For some reason, I still have to understand why, at a certain point, the serial stops receiving data or, at least, the rx2[] buffer stays empty even if I'm sending data.
Is there a way to check if the UART goes in error and, at least, reset it to make it work again?
After some investigation, I found out that the main issue is that RxXferCount goes to zero for some reason. This put the RxState to HUAL_UART_STATE_READY instead of putting the state back to BUSY RX.
The CR1 register has also the bit 2 RE: Receiver enable set to 0 and the ISR register shows both FE: Framing error and NF: START bit Noise detection flag.
The main issue is that when everything I've just described happens, the `HAL_UART_ErrorCallback` is not called
Staying in debug I've noticed that the only callback my code enters in is the `USART3_8_IRQhandler`
From what I understand is that with `RxXferCount=0` the micro do not automatically clear the errors and goes back to the RX mode, but stays stuck in the situation I've just described
