Posted on November 17, 2017 at 10:33Hello,
I finally got the solution, I found what the problem was!
Usually, the CS signal goes from 1 to 0, then MISO and MOSI communicates, and once the communication finishes CS signal goes from 0 to 1, and the STM32F429 continues with the rest of the tasks...
This was happening every 150 ms, that's the period of thime both uC are communicating. But the STM32 uC has another tasks with more priority than SPI communication.
When one of this higher priority starts during SPI communication, and once this higher priority is done then the uC continues with the task was doing ( it was SPI),
obviously
this frame is lost and 'HAL_SPI_ErrorCallback' is executed, and then SPI is restarted.If SPI is restarted when CS signal is 1, (spi idle), then there is no problem, SPI is restarted properly and the next frame will be received without problem. BUT if SPI is restarted when CS signal is 0 (STM32 SPI is selected and ready to communicate) then the STM32 is waiting to send and receive an amount of bytes but it will receives less, so an a mismatch of communication bytes is the key of the PROBLEM.
I have solved this issue just adding:
void HAL_SPI_ErrorCallback(SPI_HandleTypeDef *hspi)
{
if(hspi -> Instance == SPI6)
{
while(HAL_GPIO_ReadPin(GPIOG, GPIO_PIN_8) != GPIO_PIN_SET) // CS signal
{
}
HAL_SPI_TransmitReceive_DMA(&hspi6, (uint8_t*)HMI_slave_TX_data, (uint8_t*)HMI_slave_RX_data,10);
}
}
I have to modify 'WHILE' in order to not stop the processor , but it is the first approximation.
Now the communication is working all the time, but some times a frame is lost (and ' HAL_SPI_ErrorCallback' is called) due to higher priority task. But it is normal, a CRC is implemented to note that.
Thansk JW to help me and support.
I hope this helps to other people.
Best regards.
Alejandro.
