写出stm32的CAN接收代码

以下是STM32的CAN接收代码示例：

#include "stm32f1xx_hal.h"

CAN_HandleTypeDef hcan;

void CAN_Init(void)
{
  hcan.Instance = CAN1;
  hcan.Init.Mode = CAN_MODE_NORMAL;
  hcan.Init.AutoBusOff = ENABLE;
  hcan.Init.AutoRetransmission = ENABLE;
  hcan.Init.AutoWakeUp = DISABLE;
  hcan.Init.ReceiveFifoLocked = DISABLE;
  hcan.Init.TimeTriggeredMode = DISABLE;
  hcan.Init.TransmitFifoPriority = DISABLE;
  hcan.Init.SyncJumpWidth = CAN_SJW_1TQ;
  hcan.Init.TimeSeg1 = CAN_BS1_8TQ;
  hcan.Init.TimeSeg2 = CAN_BS2_7TQ;
  hcan.Init.Prescaler = 4;

  if (HAL_CAN_Init(&hcan) != HAL_OK)
  {
    Error_Handler();
  }

  CAN_FilterTypeDef filter;
  filter.FilterBank = 0;
  filter.FilterMode = CAN_FILTERMODE_IDMASK;
  filter.FilterScale = CAN_FILTERSCALE_32BIT;
  filter.FilterIdHigh = 0x0000;
  filter.FilterIdLow = 0x0000;
  filter.FilterMaskIdHigh = 0x0000;
  filter.FilterMaskIdLow = 0x0000;
  filter.FilterFIFOAssignment = CAN_RX_FIFO0;
  filter.FilterActivation = ENABLE;
  filter.SlaveStartFilterBank = 14;

  if (HAL_CAN_ConfigFilter(&hcan, &filter) != 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();
  }
}

void HAL_CAN_RxFifo0MsgPendingCallback(CAN_HandleTypeDef *hcan)
{
  CAN_RxHeaderTypeDef rxHeader;
  uint8_t rxData[8];

  if (HAL_CAN_GetRxMessage(hcan, CAN_RX_FIFO0, &rxHeader, rxData) != HAL_OK)
  {
    Error_Handler();
  }

  // 处理接收到的CAN数据
}

int main(void)
{
  HAL_Init();
  CAN_Init();

  while (1)
  {

  }
}

以上代码实现了CAN的初始化和接收处理，可以根据需要进行修改和扩展。