求懂modbus协议的大神救命我modbus发送报文写完了我现在要整如何接收到返回的报文然后解析出来怎么写

小菜鸟ning · 发表于 2015-11-22 20:04:57

#include "stm32f10x.h"
#include "stm32f10x_gpio.h"
#include "stm32f10x_tim.h"
#include "stm32f10x_usart.h"
#include "delay.h"
#include "crc.h"
#include "stdio.h"
u8 counter;
u8 recvBuff[256]={0};
int MODBUS(u8* recvBuff,int len,u8 id,u8 D,u8 reg);
void UART2Write(u8* data,int len);
void UART2_SendByte(u8 Data);
void USART_config(u32 bound)
{
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
//RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2|RCC_APB2Periph_GPIOA,ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO,ENABLE); //这里一定要配置复用 AFIO
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2 ,ENABLE);
USART_DeInit(USART2);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;
GPIO_InitStructure.GPIO_Mode =GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;
GPIO_InitStructure.GPIO_Mode =GPIO_Mode_IN_FLOATING;
GPIO_Init(GPIOA, &GPIO_InitStructure);
USART_InitStructure.USART_BaudRate = bound;
USART_InitStructure.USART_WordLength = USART_WordLength_8b; //字长为8位数据格式
USART_InitStructure.USART_StopBits = USART_StopBits_1; // 一个停止位
USART_InitStructure.USART_Parity = USART_Parity_No; //无奇偶校验位
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None; //为硬盘数据流控制
USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx; //接收发送模式
NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);
USART_Init(USART2, &USART_InitStructure);
USART_Cmd(USART2, ENABLE);
}
void Timer_Config(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3,ENABLE);//Timer3_Clock=APB1*2;
TIM_DeInit(TIM3); //复位定时器
TIM_TimeBaseStructure.TIM_Period=4999; //定时器初始值
TIM_TimeBaseStructure.TIM_Prescaler=(7200-1); //时钟预分频
TIM_TimeBaseStructure.TIM_ClockDivision=TIM_CKD_DIV1; // 时钟分割
TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up; //向上计数模式
TIM_TimeBaseInit(TIM3,&TIM_TimeBaseStructure); //初始化定时器的值
TIM_ClearFlag(TIM3,TIM_FLAG_Update); //清除定时器中断标志
TIM_ITConfig(TIM3,TIM_IT_Update,ENABLE); //使能中断
TIM_Cmd(TIM3,ENABLE); //开启时钟
}
void NVIC_Config(void)
{
NVIC_InitTypeDef NVIC_InitStructure;
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);
NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
void TIM3_IRQHandler(void)//定时器中断函数
{

if (TIM_GetITStatus(TIM3, TIM_IT_Update) != RESET) // 跟下面一句连在一起用的判断是否中断有触发，出发后就清除
{
TIM_ClearITPendingBit(TIM3, TIM_IT_Update); //清除中断标志
counter++;

}
}
/*串口中断函数什么时候用的到的呢就是说main函数里面一直在执行自己的东西
然后突然有东西给单片机啦下面判断if（）发送寄存器空被触发就暂停工作执行中断函数*/
void USART2_IRQHandler(void)
{
u8 RX_dat;
if(USART_GetITStatus(USART2,USART_IT_RXNE)!=RESET) //判断发生接收中断
{
RX_dat = USART_ReceiveData(USART2);
}
}
int main(void)
{
int len = 0;
Timer_Config();
NVIC_Config();
SystemInit();
USART_config(9600);
delay_init(72);
while(1)
{
MODBUS( recvBuff,8, 0x01, 0x02, 0x08);
len =8 ;
UART2Write(recvBuff,len);
delay_ms(50);
}
}

/* 下面是一个发送数组的函数首先先传递第二个函数是一个字节一个字节的发送*/
void UART2Write(u8* data,int len)
{
u8 i;
for(i =0;i<8;i++)
{
UART2_SendByte(data);
}
}
void UART2_SendByte(u8 Data) //把上面收到的字节一个一个的发送出去
{
while (!(USART2->SR & USART_FLAG_TXE)); //usart2->SR是串口状态寄存器 USART_FLAG_TXE传输数据寄存器空标记
USART_SendData(USART2, Data);
}
int MODBUS(u8* recvBuff,int len,u8 id,u8 D,u8 reg)
{
if(len >= 8)
{
u16 crc;
recvBuff[0] = id;
recvBuff[1] = 3;
recvBuff[2] = (unsigned char)(D >> 8); //右移八位[2][3]是起始地址占两个字节右移八位取高八位
recvBuff[3] = (unsigned char)(D & 0xFF);
recvBuff[4] = (unsigned char)(reg >> 8); //同上
recvBuff[5] = (unsigned char)(reg & 0xFF);
crc=CRC16(recvBuff,6) ; // 校验前面的数字CRC的计算函数
recvBuff[6] = (crc>>8); // 计算出的高八位给第六位
recvBuff[7] = (u8)crc; //计算出的第八位给第七位
}
else
return 0;
return 8;
}