这个是MODBUS控制电磁阀的一个程序。其中还有AD采集的部分。对CRC校验用查表的方法。至于怎样把校验的结果拆分成高低位字节，再发送，看程序吧。
#include"reg51.h"
#include"intrins.h"
#define uchar unsigned char
#define uint unsigned int
#define Pressure P0
////////////////
/////////////////////
uchar addr
uchar Pressure_updata
uchar Pressure_lowdata
/////////////////
sbit Dcf_open=P1^0//电磁阀开启
sbit Dcf_close=P1^1//电磁阀关闭
bit dr
bit Dcf_state=1
bit Halfsecond=0
bit Onesecond=0
//////////////////////////////
sbit Mydress_set=P2^5
sbit P_uplimite =P2^6
sbit P_lowlimite=P2^7
sbit Stor=P3^2
sbit myint=P3^3
sbit ADC_wr =P3^6
sbit ADC_rd =P3^7
sbit xuantong =P1^7
sbit addrset=P1^2
sbit upset=P1^3
sbit lowset=P1^4
/////////////////////////
uchar code Myreturnstateopen[3] ={0x01,0x01,0x00}
uchar code Myreturnstateclose[3]={0x01,0x01,0x01}
uchar code Myreturnopen[3] ={0x01,0x01,0x10}
uchar code Myreturnclose[3]={0x01,0x01,0x20}
uchar receive_count=0
uchar mysend[6],aq[8]
uchar Adc_value
unsigned long Mycount=0
uchar jishi=0 //定时一秒计数
uint crc=0,myaw=0
uint crc16(unsigned char *puchMsg, unsigned int usDataLen)
bit yifasong=0
void Beginsend( uchar Me )
bit check_modbus()
void Open_dcf()
void Close_dcf()
void timer0()
void uart_init(void)
void delay(uint z)
void Read_adc()
void Tosend()
/////////
/*************延时*****************/
void delay(uint z)
{
uchar y
while(z--)
for(y=113y>0y--)
}
/************串口初始化*****************/
void uart_init(void) interrupt 4 using 1
{
if(RI)
{
aq[receive_count]=SBUF
RI=0
receive_count++
if(0==receive_count%8)
{
yifasong=0
receive_count=0
}
RI=0
}
}
/**************定时器0初始化**************/
void timer0() interrupt 1 using 1
{
TH0=0x4b
TL0=0x63
jishi++
if (0==jishi%10) {
Halfsecond=1
aq[0]=0aq[1]=0aq[2]=0aq[3]=0aq[4]=0aq[5]=0aq[6]=0aq[7]=0receive_count=0
}
}
void Read_adc()
{
ADC_rd=1
ADC_wr=1
_nop_()
_nop_()
_nop_()
_nop_()
myint=1
P0=0xff
ADC_wr=0
_nop_()
_nop_()
_nop_()
_nop_()
ADC_wr=1
while( myint==1)
ADC_rd=0
_nop_()
_nop_()
_nop_()
_nop_()
_nop_()
Adc_value=P0 //读出的数据赋与addate
ADC_rd=1
}
void Open_dcf()
{
Dcf_open=0 delay(1200)Dcf_open=1 Dcf_state=1
}
void Close_dcf()
{
Dcf_close=0 delay(1200)Dcf_close=1Dcf_state=0
}
void Read_Pressure()
{
Read_adc()
if (Dcf_state)
{
if((Adc_value<Pressure_lowdata)|| (Adc_value>Pressure_updata))
{
delay(1200)
if((Adc_value<Pressure_lowdata)|| (Adc_value>Pressure_updata)) { Close_dcf()}
}
else
{ }
}
else
{
if((Adc_value>Pressure_lowdata)&&(Adc_value<Pressure_updata))
{ delay(1200)
if((Adc_value>Pressure_lowdata)&&(Adc_value<Pressure_updata)) { Open_dcf()}
}
else
}
}
void initialize()
{
TMOD=0x20
SCON=0x50//串口通讯方式1
TH1=0xfd//波特率9600
TL1=0xfd
TH0=0x4b
TL0=0x63
TI=0//发送中断标志位清零
RI=0//接收中断标志位清零
Mydress_set=1P_lowlimite=1P_uplimite=1xuantong=1
Mydress_set=0delay(20)addrset=1delay(20)addr=P0
delay(20)
addrset=0Mydress_set=1delay(200)P0=0xff
P_lowlimite=0delay(20)lowset=1delay(20)Pressure_lowdata=P0
delay(20)
lowset=0P_lowlimite=1P0=0xff
P_uplimite=0delay(20)upset=1Pressure_updata=P0delay(20)upset=0P_uplimite=1P0=0xff
xuantong=0
}
void main(void)
{
IE=0x92
TR0=1TR1=1
// WDTRST=0x1E
// WDTRST=0xE1//初始化看门狗
initialize()
Stor=0
for() { // WDTRST=0x1E
//WDTRST=0xE1//喂狗指令
if (Halfsecond==1) {
Halfsecond=0
Read_Pressure()
}
//够一秒开始转换
if(receive_count==0&&(yifasong==0))
{ Stor=0
dr= check_modbus()
if (dr&&addr==aq[0])
{ if(aq[1]==0x05)
switch ( aq[3])
{
case 0x00 :
if(!Dcf_state) Open_dcf()
Beginsend(0) break
case 0x01 :
if(Dcf_state) Close_dcf()
Beginsend(1)
break
default :
}
else if(aq[1]==0x01)
{
if(Dcf_state)
{ Beginsend(2)
}
else
{ Beginsend(3)
}
}
else
}
else
}
}
}
void Beginsend(uchar Me )
{
uchar i
ES=0Stor=1
TI=0
mysend[0]=addr
switch(Me)
{
case 0:
{ for(i=1i<4i++)
{
mysend[i] = Myreturnopen[i-1]
}
i=0
}break
case 1:
{for(i=1i<4i++)
{
mysend[i] = Myreturnclose[i-1]
} i=0}break
case 2:
{ for(i=1i<4i++)
{
mysend[i] = Myreturnstateopen[i-1]
} i=0}break
case 3:
{for(i=1i<4i++)
{
mysend[i] = Myreturnstateclose[i-1]
}i=0}break
default : }
myaw=crc16(mysend,4)
mysend[4] =myaw&0x00ff
mysend[5] =(myaw>>8)&0x00ff
for(i=0i<6i++)
{
SBUF=mysend[i]
while(TI!=1)
TI=0
}
Stor=0
ES=1
yifasong=1
}
bit check_modbus()
{
uchar m,n
crc=crc16(aq,6)
m=crcn=crc>>8&0x00ff
if(aq[6]==m&&aq[7]==n)
return 1
else
return 0
}
uint crc16(uchar *puchMsg, uint usDataLen)
{
uchar uchCRCHi = 0xFF //* 高CRC字节初始化
uchar uchCRCLo = 0xFF //* 低CRC 字节初始化
unsigned long uIndex // CRC循环中的索引
while (usDataLen--) // 传输消息缓冲区
{
uIndex = uchCRCHi ^ *puchMsg++ // 计算CRC
uchCRCHi = uchCRCLo ^ auchCRCHi[uIndex]
uchCRCLo = auchCRCLo[uIndex]
}
return (uchCRCHi | uchCRCLo<<8)
}
/***********************CRC校验*************************/
// CRC 高位字节值表
刚好我在弄crc校验。给你一段代码。我也是冲网上抄过来的。验证过了。unsigned short crc16
static uchar code auchCRCHi[256] = {
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
}
// CRC 低位字节值表
static uchar code auchCRCLo[256] = {
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
}
//CRC校验的函数
unsigned short CRC16(unsigned char *puchMsg, unsigned short usDataLen)
{
unsigned char uchCRCHi = 0xFF /* 高CRC字节初始化 */
unsigned char uchCRCLo = 0xFF /* 低CRC 字节初始化 */
unsigned uIndex /* CRC循环中的索引 */
while (usDataLen--) /* 传输消息缓冲区 */
{
uIndex = uchCRCHi ^ *puchMsg++ /* 计算CRC */
uchCRCHi = uchCRCLo ^ auchCRCHi[uIndex]
uchCRCLo = auchCRCLo[uIndex]
}
return (uchCRCHi <<8 | uchCRCLo)
}
调用方式：dd=CRC16(tmp,x)；
远距离通信，不能正常接受，这是常有的事。发送函数，必须多次发送，只有当收到正确的回信后，才停止发送，并返回正确传送标志。
发送函数，发送了一定的次数后，都没有收到回信，则返回错误的标志。
上层函数，根据标志，在屏幕上加以提示，指示 *** 作者进行下一步的 *** 作。
另外，在中断函数中，加上了长延时，delay(2000)，也是个败笔，可能会错过很多应该接受的东西。
欢迎分享，转载请注明来源：内存溢出
微信扫一扫
支付宝扫一扫
评论列表（0条）