Odd and Even CAN bus ID's FilterConfig

[JBond.1]

Hi, I am working with STM32F103 and configured CAN filter to receive ODD and EVEN ID's to FIFO0 and FIFO1 accordingly:

 CAN_FilterTypeDef sFilterConfig;
 sFilterConfig.SlaveStartFilterBank = 28;
 sFilterConfig.FilterActivation = ENABLE;
 sFilterConfig.FilterMode = CAN_FILTERMODE_IDMASK;
 sFilterConfig.FilterScale = CAN_FILTERSCALE_32BIT;
 sFilterConfig.FilterBank = 0;
 sFilterConfig.FilterFIFOAssignment = CAN_RX_FIFO0;
 // odd IDs to FIFO0
 sFilterConfig.FilterIdHigh = (0x00000001 << 5);
 sFilterConfig.FilterIdLow = (0x00000000 << 5);
 sFilterConfig.FilterMaskIdHigh = (0x00000001 << 5);
 sFilterConfig.FilterMaskIdLow = (0x00000000 << 5);
 
 if (HAL_CAN_ConfigFilter(&hcan, &sFilterConfig) != HAL_OK)
 {
 Error_Handler();
 }
 
 sFilterConfig.FilterBank = 1;
 sFilterConfig.FilterFIFOAssignment = CAN_RX_FIFO1;
 // even IDs to FIFO1
 sFilterConfig.FilterIdHigh = (0x00000000 << 5);
 sFilterConfig.FilterIdLow = (0x00000000 << 5);
 sFilterConfig.FilterMaskIdHigh = (0x00000001 << 5);
 sFilterConfig.FilterMaskIdLow = (0x00000000 << 5);
 
 if (HAL_CAN_ConfigFilter(&hcan, &sFilterConfig) != HAL_OK)
 {
 Error_Handler();
 }
	
 if (HAL_CAN_Start(&hcan) != HAL_OK)
 {
 Error_Handler();
 }
	
 if (HAL_CAN_ActivateNotification(&hcan, CAN_IT_RX_FIFO0_MSG_PENDING) != HAL_OK)
 {
 Error_Handler();
 }
	
 if (HAL_CAN_ActivateNotification(&hcan, CAN_IT_RX_FIFO1_MSG_PENDING) != HAL_OK)
 {
 Error_Handler();
 }

Its not that easy to understand STM32 filter mask and ID's. So is filter configured correctly to receive ODD and EVEN ID's to FIFO0 and FIFO1?

Also previously I was using only FIFO0 to catch all CAN bus ID's. Does splitting filters to ODD and EVEN ID's into FIFO0 and FIFO1 should give better performance and less overflow chance?

[Bowman32]

Hi @Community member​ 

It seems all code configuration is correct. However, you can refer to STM32F103 reference manual RM0008 section 24.7.4 Identifier filtering.

Bouraoui