STM32 CAN主站编写示例

以下是一个简单的STM32 CAN主站编写示例，使用标准的CAN总线协议，发送一个包含“Hello World！”的CAN消息：

#include "stm32f4xx.h"

void CAN_Config(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;
  NVIC_InitTypeDef NVIC_InitStructure;
  CAN_InitTypeDef CAN_InitStructure;
  CAN_FilterInitTypeDef CAN_FilterInitStructure;

  // 使能GPIO和CAN总线时钟
  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_CAN1, ENABLE);

  // 配置GPIO引脚
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
  GPIO_Init(GPIOB, &GPIO_InitStructure);

  // 将GPIO引脚与CAN总线功能映射
  GPIO_PinAFConfig(GPIOB, GPIO_PinSource8, GPIO_AF_CAN1);
  GPIO_PinAFConfig(GPIOB, GPIO_PinSource9, GPIO_AF_CAN1);

  // 配置CAN总线
  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_9tq;
  CAN_InitStructure.CAN_BS2 = CAN_BS2_4tq;
  CAN_InitStructure.CAN_Prescaler = 2;
  CAN_Init(CAN1, &CAN_InitStructure);

  // 配置CAN过滤器
  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);

  // 配置CAN中断
  NVIC_InitStructure.NVIC_IRQChannel = CAN1_RX0_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);
}

void CAN_SendMessage(uint8_t *data, uint8_t len)
{
  CAN_InitTypeDef CAN_InitStructure;
  CanTxMsg TxMessage;

  // 配置CAN总线
  CAN_StructInit(&CAN_InitStructure);

  // 填充CAN消息
  TxMessage.StdId = 0x123;
  TxMessage.ExtId = 0x00;
  TxMessage.RTR = CAN_RTR_DATA;
  TxMessage.IDE = CAN_ID_STD;
  TxMessage.DLC = len;
  for (int i = 0; i < len; i++)
  {
    TxMessage.Data[i] = data[i];
  }

  // 发送CAN消息
  CAN_Transmit(CAN1, &TxMessage);
}

int main(void)
{
  uint8_t data[] = "Hello World!";
  uint8_t len = sizeof(data) - 1;

  // 初始化CAN总线
  CAN_Config();

  // 发送CAN消息
  CAN_SendMessage(data, len);

  while (1)
  {
    // 等待CAN消息发送完成
  }
}

以上示例中，首先调用`CAN_Config`函数进行CAN总线的初始化和配置。然后，调用`CAN_SendMessage`函数发送一个包含“Hello World！”的CAN消息。在`main`函数中，先初始化CAN总线，然后发送CAN消息，并在一个无限循环中等待CAN消息发送完成。