Implementing CAN on Nucleo F439Z, but the Callback function is never called.

Hello,

I am trying to put in place CAN protocol on my Nucleo but I am facing a problem. The callback function is never called consequently the buffer of reception is always empty.

I try a lot of ways to fix the problem but no way.

Any help or suggestion will be appreciated!!

Here is my code!!

Thank you !!

CAN_HandleTypeDef hcan1;
UART_HandleTypeDef huart3;
 
CAN_TxHeaderTypeDef pHeader;
CAN_RxHeaderTypeDef rHeader;
 
uint32_t pTxMailbox;
uint8_t count[8],r[8];
uint8_t flag =0;
uint32_t RxFifo;
 
// main function 
 
int main(void)
{
	CAN_FilterTypeDef sFilterConfig;
 
 HAL_Init();
 
 
 SystemClock_Config();
 
 MX_GPIO_Init();
 MX_USART3_UART_Init();
 MX_CAN1_Init();
 printf("Debug \r\n");
 
 pHeader.DLC= 8;
 pHeader.IDE =CAN_ID_STD;
 pHeader.RTR=CAN_RTR_DATA;
 pHeader.StdId=0x00;
 
 
 sFilterConfig.FilterFIFOAssignment=CAN_FILTER_FIFO0;
 sFilterConfig.FilterIdHigh=0;
 sFilterConfig.FilterIdLow=0; 
 
 sFilterConfig.FilterMaskIdHigh=0;
 sFilterConfig.FilterMaskIdLow=0x00;
 sFilterConfig.FilterMode=CAN_FILTERMODE_IDMASK;
 sFilterConfig.FilterScale=CAN_FILTERSCALE_32BIT;
 sFilterConfig.FilterActivation=CAN_FILTER_ENABLE;
 sFilterConfig.SlaveStartFilterBank = 0;
 
 if (HAL_CAN_ConfigFilter(&hcan1, &sFilterConfig) != HAL_OK)
	 Error_Handler();
 
 
 if (HAL_CAN_Start(&hcan1) !=HAL_OK)
	 Error_Handler();
 
 if (HAL_CAN_ActivateNotification(&hcan1, CAN_IT_RX_FIFO0_MSG_PENDING) != HAL_OK)
	 Error_Handler();
 
 
 
 while (1)
 {
	 if (HAL_GPIO_ReadPin(USER_Btn_GPIO_Port, USER_Btn_Pin) == NOPRESSED)
	 {
	 		count[0] = 0xAB;
	 		count[1] = 0xAD;
 
			printf("%d", count[0]);
			printf("Debug 2 \r\n");
 
 
	 		if (HAL_CAN_AddTxMessage(&hcan1, &pHeader, count, &pTxMailbox) != HAL_OK)
	 			 Error_Handler();
 
	 		HAL_GPIO_WritePin(GPIOB, LD1_Pin,GPIO_PIN_SET);
			HAL_Delay(500);
	 }
 
	 HAL_GPIO_WritePin(GPIOB, LD1_Pin,GPIO_PIN_RESET);
 
	 if (flag)
	 {
		 flag = 0;
		 printf("%d", r[0]);
		 HAL_GPIO_WritePin(GPIOB, LD3_Pin, GPIO_PIN_SET);
		 HAL_Delay(10);
	 }
 
	 HAL_GPIO_WritePin(GPIOB, LD3_Pin, GPIO_PIN_RESET);
 }
}