stm32基于Mobus协议的485通信

 

//////////////////////////////////////////////////////////////////////////// 

#include "USART2.h"
#include "usart.h"
#include "delay.h"

 

u32 RS485_Baudrate=9600;//通讯波特率
u8 RS485_Parity=0;//0无校验；1奇校验；2偶校验
u8 RS485_Addr=02;//从机地址
u16 RS485_Frame_Distance=4;//数据帧最小间隔（ms),超过此时间则认为是下一帧

u8 RS485_RX_BUFF[2048];//接收缓冲区2048字节
u16 RS485_RX_CNT=0;//接收计数器
u8 RS485_FrameFlag=0;//帧结束标记
u8 RS485_TX_BUFF[2048];//发送缓冲区
u16 RS485_TX_CNT=0;//发送计数器

////////////////////////////////////////////////////////////////////////////////////////////////////////////
//Modbus寄存器和单片机寄存器的映射关系
vu32 *Modbus_InputIO[100];//输入开关量寄存器指针(这里使用的是位带操作)
vu32 *Modbus_OutputIO[100];//输出开关量寄存器指针(这里使用的是位带操作)
u16 *Modbus_HoldReg[1000];//保持寄存器指针
u32 testData1=1201,testData2=1002,testData3=2303,testData4=8204;
const u8 auchCRCHi[] = {
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40,
0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40,
0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40,
0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,0x80, 0x41, 0x00, 0xC1, 0x81, 0x40} ;

const u8 auchCRCLo[] = {
0x00, 0xC0, 0xC1, 0x01, 0xC3, 0x03, 0x02, 0xC2, 0xC6, 0x06,0x07, 0xC7, 0x05, 0xC5, 0xC4, 0x04, 0xCC, 0x0C, 0x0D, 0xCD,
0x0F, 0xCF, 0xCE, 0x0E, 0x0A, 0xCA, 0xCB, 0x0B, 0xC9, 0x09,0x08, 0xC8, 0xD8, 0x18, 0x19, 0xD9, 0x1B, 0xDB, 0xDA, 0x1A,
0x1E, 0xDE, 0xDF, 0x1F, 0xDD, 0x1D, 0x1C, 0xDC, 0x14, 0xD4,0xD5, 0x15, 0xD7, 0x17, 0x16, 0xD6, 0xD2, 0x12, 0x13, 0xD3,
0x11, 0xD1, 0xD0, 0x10, 0xF0, 0x30, 0x31, 0xF1, 0x33, 0xF3,0xF2, 0x32, 0x36, 0xF6, 0xF7, 0x37, 0xF5, 0x35, 0x34, 0xF4,
0x3C, 0xFC, 0xFD, 0x3D, 0xFF, 0x3F, 0x3E, 0xFE, 0xFA, 0x3A,0x3B, 0xFB, 0x39, 0xF9, 0xF8, 0x38, 0x28, 0xE8, 0xE9, 0x29,
0xEB, 0x2B, 0x2A, 0xEA, 0xEE, 0x2E, 0x2F, 0xEF, 0x2D, 0xED,0xEC, 0x2C, 0xE4, 0x24, 0x25, 0xE5, 0x27, 0xE7, 0xE6, 0x26,
0x22, 0xE2, 0xE3, 0x23, 0xE1, 0x21, 0x20, 0xE0, 0xA0, 0x60,0x61, 0xA1, 0x63, 0xA3, 0xA2, 0x62, 0x66, 0xA6, 0xA7, 0x67,
0xA5, 0x65, 0x64, 0xA4, 0x6C, 0xAC, 0xAD, 0x6D, 0xAF, 0x6F,0x6E, 0xAE, 0xAA, 0x6A, 0x6B, 0xAB, 0x69, 0xA9, 0xA8, 0x68,
0x78, 0xB8, 0xB9, 0x79, 0xBB, 0x7B, 0x7A, 0xBA, 0xBE, 0x7E,0x7F, 0xBF, 0x7D, 0xBD, 0xBC, 0x7C, 0xB4, 0x74, 0x75, 0xB5,
0x77, 0xB7, 0xB6, 0x76, 0x72, 0xB2, 0xB3, 0x73, 0xB1, 0x71,0x70, 0xB0, 0x50, 0x90, 0x91, 0x51, 0x93, 0x53, 0x52, 0x92,
0x96, 0x56, 0x57, 0x97, 0x55, 0x95, 0x94, 0x54, 0x9C, 0x5C,0x5D, 0x9D, 0x5F, 0x9F, 0x9E, 0x5E, 0x5A, 0x9A, 0x9B, 0x5B,
0x99, 0x59, 0x58, 0x98, 0x88, 0x48, 0x49, 0x89, 0x4B, 0x8B,0x8A, 0x4A, 0x4E, 0x8E, 0x8F, 0x4F, 0x8D, 0x4D, 0x4C, 0x8C,
0x44, 0x84, 0x85, 0x45, 0x87, 0x47, 0x46, 0x86, 0x82, 0x42,0x43, 0x83, 0x41, 0x81, 0x80, 0x40} ;

u16 CRC_Compute(u8 *puchMsg, u16 usDataLen)
{
        u8 uchCRCHi = 0xFF ;
        u8 uchCRCLo = 0xFF ;
        u32 uIndex ;
        while (usDataLen--)
        {
                uIndex = uchCRCHi ^ *puchMsg++ ;
                uchCRCHi = uchCRCLo ^ auchCRCHi[uIndex] ;
                uchCRCLo = auchCRCLo[uIndex] ;
        }
        return ((uchCRCHi<< 8)  | (uchCRCLo)) ;
}//uint16 crc16(uint8 *puchMsg, uint16 usDataLen)
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//初始化USART2
void RS485_Init(void)
{
        GPIO_InitTypeDef GPIO_InitStructure;
        USART_InitTypeDef USART_InitStructure;
        NVIC_InitTypeDef NVIC_InitStructure;
        RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE);
        RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2,ENABLE);
       
        GPIO_InitStructure.GPIO_Pin=GPIO_Pin_2;//PA2（TX）复用推挽输出
        GPIO_InitStructure.GPIO_Mode=GPIO_Mode_AF_PP;
        GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz;
        GPIO_Init(GPIOA,&GPIO_InitStructure);
        GPIO_SetBits(GPIOA,GPIO_Pin_2);//默认高电平
       
        GPIO_InitStructure.GPIO_Pin=GPIO_Pin_3;//PA3（RX）输入上拉
        GPIO_InitStructure.GPIO_Mode=GPIO_Mode_IN_FLOATING;   //修改原GPIO_Mode_IPU（输入上拉）->GPIO_Mode_IN_FLOATING(浮空输入)/////////////////////////////////////////////
        GPIO_Init(GPIOA,&GPIO_InitStructure);
    
//        USART_DeInit(USART2);//复位串口2
        USART_InitStructure.USART_BaudRate=RS485_Baudrate;
        USART_InitStructure.USART_HardwareFlowControl=USART_HardwareFlowControl_None;
        USART_InitStructure.USART_WordLength=USART_WordLength_8b;
        USART_InitStructure.USART_StopBits=USART_StopBits_1;
        USART_InitStructure.USART_Mode=USART_Mode_Rx|USART_Mode_Tx;//收发模式
        switch(RS485_Parity)
        {
                case 0:USART_InitStructure.USART_Parity=USART_Parity_No;break;//无校验
                case 1:USART_InitStructure.USART_Parity=USART_Parity_Odd;break;//奇校验
                case 2:USART_InitStructure.USART_Parity=USART_Parity_Even;break;//偶校验
        }
        USART_Init(USART2,&USART_InitStructure);
       
        USART_ClearITPendingBit(USART2,USART_IT_RXNE);
        USART_ITConfig(USART2,USART_IT_RXNE,ENABLE);//使能串口2接收中断
       
        NVIC_InitStructure.NVIC_IRQChannel=USART2_IRQn;
        NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=2;
        NVIC_InitStructure.NVIC_IRQChannelSubPriority=2;
        NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;
        NVIC_Init(&NVIC_InitStructure);
       
        USART_Cmd(USART2,ENABLE);//使能串口2
//        RS485_TX_EN=1;//默认为接收模式
       
        Timer2_Init();//定时器2初始化，用于监视空闲时间
        //Modbus_RegMap();//Modbus寄存器映射
}
void Timer2_Init(void)
{
        TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
        NVIC_InitTypeDef NVIC_InitStructure;

        RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE); //TIM7时钟使能

        //TIM7初始化设置
        TIM_TimeBaseStructure.TIM_Period = RS485_Frame_Distance*10; //设置在下一个更新事件装入活动的自动重装载寄存器周期的值
        TIM_TimeBaseStructure.TIM_Prescaler =7199; //设置用来作为TIMx时钟频率除数的预分频值 设置计数频率为10kHz
        TIM_TimeBaseStructure.TIM_ClockDivision = 0; //设置时钟分割:TDTS = Tck_tim
        TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;  //TIM向上计数模式
        TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure); //根据TIM_TimeBaseInitStruct中指定的参数初始化TIMx的时间基数单位

        TIM_ITConfig( TIM2, TIM_IT_Update, ENABLE );//TIM7 允许更新中断

        //TIM7中断分组配置
        NVIC_InitStructure.NVIC_IRQChannel =TIM2_IRQn;  //TIM7中断
        NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;  //先占优先级2级
        NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;  //从优先级3级
        NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道被使能
        NVIC_Init(&NVIC_InitStructure);  //根据NVIC_InitStruct中指定的参数初始化外设NVIC寄存器                                                                 
}
//////////////////////////////////////////////////////////////////////////////
//发送n个字节数据
//buff:发送区首地址
//len：发送的字节数
void RS485_SendData(u8 *buff,u8 len)
{
//        RS485_TX_EN=1;//切换为发送模式
        while(len--)
        {
                while(USART_GetFlagStatus(USART2,USART_FLAG_TXE)==RESET);//等待发送区为空
                USART_SendData(USART2,*(buff++));
        }
        while(USART_GetFlagStatus(USART2,USART_FLAG_TC)==RESET);//等待发送完成
}
void USART2_IRQHandler(void)//串口2中断服务程序
{
          
        u8 res;
        u8 err;
        
        if(USART_GetITStatus(USART2,USART_IT_RXNE)!=RESET)
        {
                if(USART_GetFlagStatus(USART2,USART_FLAG_NE|USART_FLAG_FE|USART_FLAG_PE)) err=1;//检测到噪音、帧错误或校验错误
                else err=0;
               
                res=USART_ReceiveData(USART2); //读接收到的字节，同时相关标志自动清除
               
                if((RS485_RX_CNT<2047)&&(err==0))
                {
                        RS485_RX_BUFF[RS485_RX_CNT]=res;
                        RS485_RX_CNT++;
                       
                        TIM_ClearITPendingBit(TIM2,TIM_IT_Update);//清除定时器溢出中断
                        TIM_SetCounter(TIM2,0);//当接收到一个新的字节，将定时器7复位为0，重新计时（相当于喂狗）
                        TIM_Cmd(TIM2,ENABLE);//开始计时
                }
        }
}
///////////////////////////////////////////////////////////////////////////////////////
//用定时器7判断接收空闲时间，当空闲时间大于指定时间，认为一帧结束
//定时器7中断服务程序        
void TIM2_IRQHandler(void)
{                                                                  
        if(TIM_GetITStatus(TIM2,TIM_IT_Update)!=RESET)
        {
                TIM_ClearITPendingBit(TIM2,TIM_IT_Update);//清除中断标志
                TIM_Cmd(TIM2,DISABLE);//停止定时器
                RS485_FrameFlag=1;//置位帧结束标记
        }
}
/////////////////////////////////////////////////////////////////////////////////////
//RS485服务程序，用于处理接收到的数据(请在主函数中循环调用)
u16 startRegAddr;
u16 RegNum;
u16 calCRC;
void RS485_Service(void)
{
        u16 recCRC;
        if(RS485_FrameFlag==1)
        {
                if(RS485_RX_BUFF[0]==RS485_Addr)//地址正确
                {
                        if((RS485_RX_BUFF[1]==01)||(RS485_RX_BUFF[1]==02)||(RS485_RX_BUFF[1]==03)||(RS485_RX_BUFF[1]==05)||(RS485_RX_BUFF[1]==06)||(RS485_RX_BUFF[1]==15)||(RS485_RX_BUFF[1]==16))//功能码正确
                  {
                                startRegAddr=(((u16)RS485_RX_BUFF[2])<<8)|RS485_RX_BUFF[3];//获取寄存器起始地址
                                if(startRegAddr<1000)//寄存器地址在范围内
                                {
                                        calCRC=CRC_Compute(RS485_RX_BUFF,RS485_RX_CNT-2);//计算所接收数据的CRC
                                        recCRC=RS485_RX_BUFF[RS485_RX_CNT-1]|(((u16)RS485_RX_BUFF[RS485_RX_CNT-2])<<8);//接收到的CRC(低字节在前，高字节在后)
                                        if(calCRC==recCRC)//CRC校验正确
                                        {
                                                                                                //LED1=0;
                                                /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
                                                switch(RS485_RX_BUFF[1])//根据不同的功能码进行处理
                                                {
                                                       
                                                               
                                                        case 16: //写多个寄存器
                                                        {
                                                                Modbus_16_Solve();
                                                                break;
                                                        }
                                                                                                                                                                                                                                 case 17: //写多个寄存器
                                                        {
                                                                Modbus_17_Solve();
                                                                break;
                                                        }
                                                                                       
                                                }
                                                //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
                                        }
                                        else//CRC校验错误
                                        {

                                                RS485_TX_BUFF[0]=RS485_RX_BUFF[0];
                                                RS485_TX_BUFF[1]=RS485_RX_BUFF[1]|0x80;
                                                RS485_TX_BUFF[2]=0x04; //异常码
                                                RS485_SendData(RS485_TX_BUFF,3);
                                        }       
                                }
                                else//寄存器地址超出范围
                                {
                                        RS485_TX_BUFF[0]=RS485_RX_BUFF[0];
                                        RS485_TX_BUFF[1]=RS485_RX_BUFF[1]|0x80;
                                        RS485_TX_BUFF[2]=0x02; //异常码
                                        RS485_SendData(RS485_TX_BUFF,3);
                                }                                               
                        }
                        else//功能码错误
                        {
                                RS485_TX_BUFF[0]=RS485_RX_BUFF[0];
                                RS485_TX_BUFF[1]=RS485_RX_BUFF[1]|0x80;
                                RS485_TX_BUFF[2]=0x01; //异常码
                                RS485_SendData(RS485_TX_BUFF,3);
                        }
          }
                               
                RS485_FrameFlag=0;//复位帧结束标志
                RS485_RX_CNT=0;//接收计数器清零            
        }               
}
//Modbus功能码16处理程序 /////////////////////////////////////////////////////////////////////////////////////////////////已验证程序OK
//写多个保持寄存器
void Modbus_16_Solve(void)
{
       
               
                RS485_TX_BUFF[0]=RS485_RX_BUFF[0];
                RS485_TX_BUFF[1]=RS485_RX_BUFF[1];
                RS485_TX_BUFF[2]=RS485_RX_BUFF[2];
                RS485_TX_BUFF[3]=RS485_RX_BUFF[3];
                RS485_TX_BUFF[4]=RS485_RX_BUFF[4];
                RS485_TX_BUFF[5]=RS485_RX_BUFF[5];
               
                calCRC=CRC_Compute(RS485_TX_BUFF,6);
                RS485_TX_BUFF[6]=(calCRC>>8)&0xFF;
                RS485_TX_BUFF[7]=(calCRC)&0xFF;
                RS485_SendData(RS485_TX_BUFF,8);
       
}
void Modbus_17_Solve(void)
{
               
                RS485_TX_BUFF[0]=RS485_RX_BUFF[0];
                RS485_TX_BUFF[1]=RS485_RX_BUFF[1];
                RS485_TX_BUFF[2]=RS485_RX_BUFF[2];
                RS485_TX_BUFF[3]=RS485_RX_BUFF[3];
                RS485_TX_BUFF[4]=RS485_RX_BUFF[4];
                RS485_TX_BUFF[5]=RS485_RX_BUFF[5];
                calCRC=CRC_Compute(RS485_TX_BUFF,6);
                RS485_TX_BUFF[6]=(calCRC>>8)&0xFF;
                RS485_TX_BUFF[7]=(calCRC)&0xFF;
                RS485_SendData(RS485_TX_BUFF,8);

 

}

 

 

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