STM32 分析DeviceNet从站报文解析

DeviceNet是一种基于CAN总线的工业控制网络协议，支持多主站和多从站之间的通信。在DeviceNet网络中，从站负责向主站提供数据，并接收来自主站的命令。以下是一个简单的STM32分析DeviceNet从站报文的示例代码：

#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_ReceiveMessage(CanRxMsg *RxMessage)
{
  // 解析DeviceNet从站报文
  uint8_t node_id = RxMessage->Data[0];
  uint16_t index = RxMessage->Data[1] | (RxMessage->Data[2] << 8);
  uint8_t sub_index = RxMessage->Data[3];
  uint8_t length = RxMessage->Data[4];
  uint8_t data[8];
  for (int i = 0; i < length; i++)
  {
    data[i] = RxMessage->Data[5 + i];
  }

  // 处理从站报文
  switch (index)
  {
    case 0x1000:
      // 处理设备类型信息
      break;

    case 0x1001:
      // 处理制造商信息
      break;

    case 0x1002:
      // 处理设备序列号信息
      break;

    case 0x1017:
      // 处理从站心跳信息
      break;

    // 其他从站报文处理
    // ...

    default:
      // 未知报文，忽略
      break;
  }
}

int main(void)
{
  // 初始化CAN总线
  CAN_Config();

  while (1)
  {
    // 等待CAN消息
  }
}

void CAN1_RX0_IRQHandler(void)
{
  CanRxMsg RxMessage;

  // 接收CAN消息
  CAN_Receive(CAN1, CAN_FIFO0, &RxMessage);

  // 处理从站报文
  CAN_ReceiveMessage(&RxMessage);

  // 清除中断标志位
  CAN_ClearITPendingBit(CAN1, CAN_IT_FMP0);
}

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，在`CAN_ReceiveMessage`函数中解析DeviceNet从站报文，并根据报文的索引值进行相应的处理。在`main`函数中，等待CAN消息的到来。当有CAN消息到来时，中断服务函数`CAN1_RX0_IRQHandler`会被调用，接收CAN消息并调用`CAN_ReceiveMessage`函数进行解析和处理。需要注意的是，在中断服务函数中需要清除中断标志位。