連接多個(gè)相同地址I2C設(shè)備的C51程序

本人初學(xué)C,曾為這個(gè)問(wèn)題大傷腦筋^_^,就是一個(gè)單片機(jī)系統(tǒng)有兩個(gè)以上的相同地址的I2C設(shè)備,無(wú)法用兩個(gè)同一對(duì)SDA/SCL引腳

#include "stc89c51.h"

#include "iic.h"

sbit scl0=P3^5;

sbit sda0 = P3^4;

sbit scl1= P3^3;

sbit sda1 = P3^2;

//這里只寫了兩個(gè)I2C設(shè)備,如果需要可以再加上 sbit scl2=xx; sbit sda2=xx; 實(shí)際上多個(gè)設(shè)備的scl腳可以共用

unsignedchariic_delay_time = 8;

voidscl(device,value);

voidsda(device,value);

bit sdasense(chardevice);

// delay

voidiic_delay(unsignedcharm)

{

unsignedcharn;

for(n=0;n

}

//

voidscl(device,value)

{

if(device==0) //設(shè)備1

scl1=value;

if(device==1) //設(shè)備2

scl2=value;

}

voidsda(device,value)

{

if(device==0) //設(shè)備1

sda1=value;

if(device==1) //設(shè)備2

sda2=value;

}

bit sdasense(chardevice)

{

switch(device)

{

case1:returnsda1;

break;

case2:returnsda2;

break;

}

}

//啟動(dòng)I2C總線的函數(shù)，當(dāng)scl為高電平時(shí)使sda產(chǎn)生一個(gè)負(fù)跳變

voidiic_start(device)

{

sda(device,1);

scl(device,1);

iic_delay(iic_delay_time);

sda(device,0);

iic_delay(iic_delay_time);

scl(device,0);

iic_delay(iic_delay_time/2);

}

//終止I2C總線，當(dāng)scl為高電平時(shí)使sda產(chǎn)生一個(gè)正跳變

voidiic_stop(device)

{

scl(device,0);

sda(device,0);

scl(device,1);

iic_delay(iic_delay_time);

sda(device,1);

iic_delay(iic_delay_time);

}

//發(fā)送應(yīng)答信號(hào)

voidiic_ack(device) {

sda(device,0);

scl(device,1);

scl(device,0);

sda(device,1);

}

//發(fā)送無(wú)應(yīng)答信號(hào)

voidiic_noack(device)

{

sda(device,1);

scl(device,1);

scl(device,0);

}

//檢測(cè)應(yīng)答信號(hào)

bit iic_testack(device)

{

bit errorbit; //真確應(yīng)答,返回0

sda(device,1);

iic_delay(iic_delay_time);

scl(device,1);

iic_delay(iic_delay_time);

errorbit=sdasense(device);

scl(device,0);

iic_delay(iic_delay_time);

return(errorbit);

}

//發(fā)送一個(gè)字節(jié)

voidiic_write8bit(device,unsignedcharinput)

{

unsignedchartemp;

for(temp=0;temp<8;temp++)

{

if((input<

sda(device,1);

else

sda(device,0);

scl(device,1);

iic_delay(iic_delay_time);

scl(device,0);

}

}

//讀一個(gè)字節(jié)

unsignedchariic_read8bit(device)

{

unsignedchartemp,rbyte=0;

for(temp=0;temp<8;temp++)

{

scl(device,1);

iic_delay(iic_delay_time);

if(sdasense(device))

rbyte=(rbyte<<1)+1;

else

rbyte=rbyte<<1;

scl(device,0);

}

return(rbyte);

}