展示一段STM32单片机CAN通信代码

以下是一个简单的基于STM32单片机的CAN通信代码示例：

#include "stm32f4xx.h"
#include "stm32f4xx_can.h"

void CAN1_Configuration(void)
{
  GPIO_InitTypeDef  GPIO_InitStructure;
  CAN_InitTypeDef   CAN_InitStructure;
  CAN_FilterInitTypeDef CAN_FilterInitStructure;
  
  /* Enable GPIO clock */
  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);
  
  /* Configure CAN RX and TX pins */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_UP;
  GPIO_Init(GPIOB, &GPIO_InitStructure);
  
  /* Connect CAN RX and TX pins to alternate function */
  GPIO_PinAFConfig(GPIOB, GPIO_PinSource8, GPIO_AF_CAN1);
  GPIO_PinAFConfig(GPIOB, GPIO_PinSource9, GPIO_AF_CAN1);
  
  /* Enable CAN clock */
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_CAN1, ENABLE);
  
  /* CAN configuration */
  CAN_InitStructure.CAN_TTCM = DISABLE;
  CAN_InitStructure.CAN_ABOM = DISABLE;
  CAN_InitStructure.CAN_AWUM = DISABLE;
  CAN_InitStructure.CAN_NART = DISABLE;
  CAN_InitStructure.CAN_RFLM = DISABLE;
  CAN_InitStructure.CAN_TXFP = ENABLE;
  CAN_InitStructure.CAN_Mode = CAN_Mode_Normal;
  CAN_InitStructure.CAN_SJW = CAN_SJW_1tq;
  CAN_InitStructure.CAN_BS1 = CAN_BS1_8tq;
  CAN_InitStructure.CAN_BS2 = CAN_BS2_7tq;
  CAN_InitStructure.CAN_Prescaler = 4;
  CAN_Init(CAN1, &CAN_InitStructure);
  
  /* CAN filter configuration */
  CAN_FilterInitStructure.CAN_FilterNumber = 0;
  CAN_FilterInitStructure.CAN_FilterMode = CAN_FilterMode_IdMask;
  CAN_FilterInitStructure.CAN_FilterScale = CAN_FilterScale_32bit;
  CAN_FilterInitStructure.CAN_FilterIdHigh = 0x0000;
  CAN_FilterInitStructure.CAN_FilterIdLow = 0x0000;
  CAN_FilterInitStructure.CAN_FilterMaskIdHigh = 0x0000;
  CAN_FilterInitStructure.CAN_FilterMaskIdLow = 0x0000;
  CAN_FilterInitStructure.CAN_FilterFIFOAssignment = 0;
  CAN_FilterInitStructure.CAN_FilterActivation = ENABLE;
  CAN_FilterInit(&CAN_FilterInitStructure);
}

int main(void)
{
  uint8_t TransmitData[8] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77};
  CAN_InitTypeDef CAN_InitStructure;
  CAN_StructInit(&CAN_InitStructure);
  CAN_InitStructure.CAN_TTCM = DISABLE;
  CAN_InitStructure.CAN_ABOM = DISABLE;
  CAN_InitStructure.CAN_AWUM = DISABLE;
  CAN_InitStructure.CAN_NART = DISABLE;
  CAN_InitStructure.CAN_RFLM = DISABLE;
  CAN_InitStructure.CAN_TXFP = ENABLE;
  CAN_InitStructure.CAN_Mode = CAN_Mode_Normal;
  CAN_InitStructure.CAN_SJW = CAN_SJW_1tq;
  CAN_InitStructure.CAN_BS1 = CAN_BS1_8tq;
  CAN_InitStructure.CAN_BS2 = CAN_BS2_7tq;
  CAN_InitStructure.CAN_Prescaler = 4;
  CAN_Init(CAN1, &CAN_InitStructure);
  
  /* Transmit CAN message */
  CanTxMsg TxMessage;
  TxMessage.StdId = 0x321;
  TxMessage.RTR = CAN_RTR_DATA;
  TxMessage.IDE = CAN_ID_STD;
  TxMessage.DLC = 8;
  for (int i = 0; i < TxMessage.DLC; i++) {
    TxMessage.Data[i] = TransmitData[i];
  }
  CAN_Transmit(CAN1, &TxMessage);
  
  /* Receive CAN message */
  CanRxMsg RxMessage;
  while (CAN_MessagePending(CAN1, CAN_FIFO0) == 0);
  CAN_Receive(CAN1, CAN_FIFO0, &RxMessage);
  
  while(1){
    // Do something
  }
}

在此代码示例中，我们使用了CAN1作为CAN总线，并在PB8和PB9引脚上配置CAN1的RX和TX线路。我们还配置了CAN的基本参数，例如CAN的模式、位时序、过滤器等。在主函数中，我们首先使用CAN_Transmit函数发送一个CAN消息，然后使用CAN_Receive函数接收CAN消息。