Impossible to read Std ID from bxCAN bus

[YAYAB.1]

bxCAN problem.

Now sending data from STM32F407 to STM32F042 via bxCAN.

In STM32F042, it is possible

• Rx interrupt
• to read sending data (0x11, 0x22)
• to read DLC (2 byte)

and oscilloscope that having CAN analyzing could read the sending ID/data correctly.

But, STM32F042 is impossible to read the standard ID. The reading ID is 0x000.

What is my mistake ?

Sending ID is 0x555.

/* receive interrupt */
void HAL_CAN_RxFifo0MsgPendingCallback(CAN_HandleTypeDef *hcan){
	CAN_RxHeaderTypeDef RxHeader;
	uint8_t 	RxData[2];
 
	if(HAL_CAN_GetRxMessage(hcan, CAN_RX_FIFO0, &RxHeader, RxData) == HAL_OK){
		id = RxHeader.StdId;
		dlc = RxHeader.DLC;
		ide = RxHeader.IDE;
		CANRxData[0] = RxData[0];
		CANRxData[1] = RxData[1];
 
		if(id == myID){
			HAL_GPIO_TogglePin(GPIOA, GPIO_PIN_0);  // Just a test
		}
	}
 
}
 
 
void CAN_Init(void){
	CAN_FilterTypeDef	filter;
 
	filter.FilterIdHigh = 0;
	filter.FilterIdLow  = 0;
	filter.FilterMaskIdHigh = 0;
	filter.FilterMaskIdLow = 0;
	filter.FilterScale = CAN_FILTERSCALE_32BIT;
	filter.FilterFIFOAssignment = CAN_FILTER_FIFO0;
	filter.FilterBank = 0;
	filter.FilterMode = CAN_FILTERMODE_IDMASK;
	filter.SlaveStartFilterBank = 14;
	filter.FilterActivation = ENABLE;
	HAL_CAN_ConfigFilter(&hcan, &filter);
 
}

Tx side code is

void CANTx(void){
 
	if(0 < HAL_CAN_GetTxMailboxesFreeLevel(&hcan1)){
		CAN1TxHeader.StdId = 0x555;
		CAN1TxHeader.RTR = CAN_RTR_DATA;
		CAN1TxHeader.IDE = CAN_ID_STD;
		CAN1TxHeader.DLC = 2;
		CAN1TxHeader.TransmitGlobalTime = DISABLE;
		CAN1TxData[0] = 0x11;
		CAN1TxData[1] = 0x22;
	    HAL_CAN_AddTxMessage(&hcan1, &CAN1TxHeader, CAN1TxData, &CAN1TxMailbox);
	}
 
}

regards.

[CMoeb.1]

Today I got the same issue. After a lot of debugging with breakpoints I found the issue.

In the declaration of HAL_CAN_GetRxMessage in your ***.hal_can.c file you can see that the method want to have a data buffer of 8. If you are using less, the method overwrites your header data. So the simple fix for this issue was.

switch this line

uint8_t 	RxData[2];

to this line

uint8_t 	RxData[8];