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How to receive a message via CAN with STM32F105

Question asked by Sandro Sartoni on Jun 21, 2017

Hi,

This is my first time programming a microcontroller, so a lot of things are still new to me and I'd like to have some infos about how to correctly receive a message via CAN.

I've read the HAL Driver documentation of my uC and what I've understood so far is that if I want to receive data in the interrupt mode, I have to use HAL_CAN_Receive_IT() function and HAL_CAN_IRQHandler() under the CAN Interrupt subroutine: everything is clear in theory, but in practice I don't know what to do.

I've initialized the CAN so that only messages from IDs 0x106 and 0x10A can be received:

 

static void MX_CAN1_Init(void)
{
  CAN_FilterConfTypeDef sFilterConfig;
  static CanRxMsgTypeDef RxMsg;
  hcan1.pRxMsg=&RxMsg;
  hcan1.Instance = CAN1;
  hcan1.Init.Prescaler = 11;
  hcan1.Init.Mode = CAN_MODE_NORMAL;
  hcan1.Init.SJW = CAN_SJW_1TQ;
  hcan1.Init.BS1 = CAN_BS1_1TQ;
  hcan1.Init.BS2 = CAN_BS2_1TQ;
  hcan1.Init.TTCM = DISABLE;
  hcan1.Init.ABOM = DISABLE;
  hcan1.Init.AWUM = DISABLE;
  hcan1.Init.NART = DISABLE;
  hcan1.Init.RFLM = DISABLE;
  hcan1.Init.TXFP = DISABLE;
  sFilterConfig.FilterNumber=0;
  sFilterConfig.FilterMode=CAN_FILTERMODE_IDMASK;
  sFilterConfig.FilterScale=CAN_FILTERSCALE_16BIT;
  sFilterConfig.FilterIdHigh=0x010A;
  sFilterConfig.FilterIdLow=0x0106;
  sFilterConfig.FilterMaskIdHigh=0x0000;
  sFilterConfig.FilterMaskIdLow=0x0000;
  sFilterConfig.FilterFIFOAssignment=0;
  sFilterConfig.FilterActivation=ENABLE;
  sFilterConfig.BankNumber=0;
  HAL_CAN_ConfigFilter(&hcan1,&sFilterConfig);
  if (HAL_CAN_Init(&hcan1) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_CAN_ConfigFilter(&hcan1,&sFilterConfig) != HAL_OK)
  {
    Error_Handler();
  }
}
But I don't know to proceed now. My while(1) section logic is:
while(1) {
   if there's a new msg then
      save it and use it to do some elaborations
   else
      do something else
}
Thanks for your help.

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