ad7745 AD7746电容检测芯片I2C接口 C51单片机驱动程序源代码.zip

//********************************** // AD7746电容检测 // IIC接口 // //***********************************// #include <reg51.h> #include <intrins.h> #include <stdio.h> sbit SCL=P2^0; sbit SDA=P2^1; sbit RDY=P3^3; #define CapDacvalue 4.97 void IIC_START(void); void IIC_STOP(void); void IICSendbyte(unsigned char ch); void IICSendbyte2(unsigned char ch); unsigned char IICRECVbyte(void); unsigned char IICWatask(void); unsigned char IICWatask2(void); void IICSendask(void); void IICSendNask(void); unsigned char SETUP_7745(unsigned char addr,unsigned char value); void GET7745value(unsigned char *p,unsigned char n); void delay(unsigned int x ); unsigned char IICreadstatus(unsigned char addr); void AD7745_RESET(); unsigned char MRD[3]={0,0,0}; unsigned char fl,flage,flag3,flag4; unsigned char stdata; unsigned long int cfregvalueH,cfregvalueM,cfregvalueL; void main() { unsigned char capdacreg; SCON=0x57; //波特率发生器 串行方式1 9600 TMOD=0x21; TH1=0xFD; TL1=0xFD; EA=1; TR1=1; IT1=1; EX1=1; fl=1; flage=1; flag3=1; flag4=1; stdata=0x01; //printf("%d,%d,%d,%d\n",fl,flage,flag3,flag4); AD7745_RESET(); capdacreg=(int)((CapDacvalue*0x7F)/17); capdacreg=0x80|capdacreg; fl=SETUP_7745(0x07,0x80); //设置CAP SETUP寄存器值 flage=SETUP_7745(0x09,0x2B); //EXCSETUP 寄存器设置 flag3=SETUP_7745(0x0A,0xA1); flag4=SETUP_7745(0x0B,capdacreg); while(1); } void AD7745_RESET(void) { IIC_START(); IICSendbyte(0xBF); IIC_STOP(); } void IIC_START(void) { //SCL=0; SDA=1; delay(2); SCL=1; delay(6); SDA=0; delay(6); SCL=0; delay(2); } void IIC_STOP(void) { // SCL=0; SDA=0; delay(2); SCL=1; delay(6); SDA=1; delay(6); SCL=0; delay(4); } void IICSendbyte(unsigned char ch) { unsigned char i; SCL=0; for (i=0;i<8;i++) { SDA=(bit)(ch&0x80); delay(6); ch<<=1; SCL=1; delay(6); SCL=0; delay(6); } delay(6); } void IICSendbyte2(unsigned char ch) { unsigned char i; SCL=0; for (i=0;i<8;i++) { SDA=(bit)(ch&0x80); delay(6); ch<<=1; SCL=1; delay(6); SCL=0; delay(6); } delay(6); } unsigned char IICRECVbyte(void) { unsigned char i; unsigned char temp=0; SCL=0; SDA=1; for (i=0;i<8;i++) { SCL=1; delay(5); temp=temp<<1; if(SDA==1) temp=temp|0x01; else temp=temp&0xfe; SCL=0; } return(temp); } unsigned char IICWatask(void) //等待AD7745向单片机发送应答信号函数 { unsigned char i=0; unsigned char flag=0x01; SCL=0; delay(2); SDA=1; SCL=1; delay(6); while((SDA==1)&&(i<250)) i++; flag=SDA; SCL=0; return(flag); } unsigned char IICWatask2(void) //等待AD7745向单片机发送应答信号函数(为避免编译报警，功能同上) { unsigned char i=0; unsigned char flag=0x01; SCL=0; delay(2); SDA=1; SCL=1; delay(6); while((SDA==1)&&(i<250)) i++; flag=SDA; SCL=0; return(flag); } void IICSendask(void) //单片机向AD7745发送应答信号 { SDA=0; delay(3); SCL=1; delay(6); delay(2); SCL=0; SDA=1; delay(3); } void IICSendNask(void) //发送非应答位 { SDA=1; delay(2); SCL=1; delay(5); SCL=0; delay(2); SDA=0; } unsigned char SETUP_7745(unsigned char addr,unsigned char value) { unsigned char flag; flag=0x01; IIC_START(); IICSendbyte2(0x90); if(IICWatask2()!=0) flag=1; else flag=0; IICSendbyte2(addr); if(IICWatask2()!=0) flag=1; else flag=0; IICSendbyte2(value); if(IICWatask2()!=0) flag=1; else flag=0; IIC_STOP(); return(flag); } void GET7745value(unsigned char *p,unsigned char n) //读取AD7745采取先写后读的方式 即先写入地址，再读相应的寄存器内容 { unsigned char i; unsigned char flagw; IIC_START(); IICSendbyte(0x90); //I2C写命令字指令 flagw=IICWatask(); IICSendbyte(0x01); //I2C写地址 flagw=IICWatask(); IIC_START(); IICSendbyte(0x91); //I2C读命令字指令 flagw=IICWatask(); for(i=0;i<n;i++) { *p=IICRECVbyte(); if(i!=n-1) IICSendask(); else IICSendNask(); p++; } IIC_STOP(); } /*unsigned char IICreadstatus(unsigned char addr) { unsigned char temp; unsigned char flagst; IICSendbyte(0x90); //I2C写命令字指令 flagst=IICWatask(); IICSendbyte(addr); //I2C写地址 flagst=IICWatask(); IIC_START(); IICSendbyte(0x91); //I2C读命令字指令 flagst=IICWatask(); temp=IICRECVbyte(); IICSendNask(); IIC_STOP(); return(temp); }*/ void intr1() interrupt 2 { float cfvalue; //stdata=IICreadstatus(0x00); delay(10); GET7745value(MRD,3); cfregvalueH=MRD[0]; cfregvalueH<<=16; cfregvalueM=MRD[1]; cfregvalueM<<=8; cfregvalueL=MRD[2]; cfregvalueH=cfregvalueH+cfregvalueM+cfregvalueL; if(cfregvalueH>=0x800000) { cfvalue=(float)((cfregvalueH-0x800000)*4.096/0x7FFFFF); cfvalue=CapDacvalue+cfvalue;} else { cfvalue=(float)((0x800000-cfregvalueH)*4.096/0x7FFFFF); cfvalue=CapDacvalue-cfvalue; } printf("%f\n",cfvalue); } void delay(unsigned int x ) { unsigned int i; i=x; while(i--); }