軟件：

a.       Keil uVision3.0；

b.      Easy 51Pro v2.0；

實驗電路原理圖：

從原理圖可看出，這次實驗在原51最小系統(tǒng)上擴展，通過引腳P0^0，P0^1分別控制AT24C01的兩引腳SCL，SDA。圖左邊加個4路撥碼開關可以動態(tài)改變AT24C01器件地址和寫保護WP狀態(tài)。

實驗以路撥碼開關打開,即A0,A1,A3,WP都為0為例.

測試成功源代碼：

文件1： Delay.c

#include "Delay.h" 

//晶振11.0592 

//延時函數(shù)

void Delay()

{}

//延時1ms

void Delay1MS(uchar n)

{

    uchar i=110; 

      while(n--)

      {

             while(i--);

      }

}

文件2： Delay.h

#ifndef _DELAY_H_

#define _DELAY_H_

#ifndef uchar

      #define uchar unsigned char      

#endif

#pragma SAVE

#pragma REGPARMS

             void Delay();               //延時函數(shù)

             void Delay1MS(uchar);             //延時1MS函數(shù)     

#pragma RESTORE

#endif

文件3：I2C.c

#include <reg51.h>

#include "Delay.h"

#include "I2C.h"

//init

void I2C_Init()

{

      SDA=1;

      SCL=1;

}

//start condition

void I2C_Start()

{

      SDA=1;

      Delay();

      SCL=1;

      Delay();

      SDA=0;

      Delay();

}

//stop condition

void I2C_Stop()

{

      SCL=0;

      Delay();

      SDA=0;

      Delay();

      SCL=1;

      Delay();

      SDA=1;

      Delay();

}

//response

bit I2C_ACK()

{

      uchar i=10;

      SCL=0;

      Delay();

      SDA=1;   //準備讀

      Delay();

      SCL=1;

      Delay();

      while(SDA && i--)

      {

             Delay();

      }

      return SDA;

}

//write byte

void I2C_WriteByte(uchar n)

{

      uchar i=8;

      while(i--)

      {

             n=n<<1;

             SCL=0;    //數(shù)據(jù)變換

             Delay();

             SDA=CY;

             Delay();

             SCL=1;    //寫數(shù)據(jù)

             Delay();

      }

}

//read byte

uchar I2C_ReadByte()

{

      uchar n=0;

      uchar i=8;

      SDA=1;

      Delay();

      while(i--)

      {

             SCL=0;    //數(shù)據(jù)變換

             Delay();

             n=(n<<1)|SDA;

             P2 = n;

             Delay();

             SCL=1;    //寫數(shù)據(jù)

             Delay();

      }

      return n;

}

文件4：I2C.h

#ifndef _I2C_H_

#define _I2C_H_

#ifndef uchar

      #define uchar unsigned char      

#endif

sbit SDA=P0^1;  //SDA

sbit SCL=P0^0;  //SCL

#pragma SAVE

#pragma REGPARMS

            void I2C_Init(void);       //init

             void I2C_Start(void);      //start condition

             void I2C_Stop(void);         //stop condition

             bit I2C_ACK(void);                  //response

             void I2C_WriteByte(uchar);       //write byte

             bit I2C_ReadBit(void);              //read bit

             uchar I2C_ReadByte(void);       //read byte

#pragma RESTORE

#endif

文件5：I2Cmain.c

#include <reg51.h>

#include "Delay.h"

#include "I2C.h"

void main()

{

      Delay1MS(250);

      I2C_Init();

       I2C_Start();

       I2C_WriteByte(0xa0);  //Write device address

       I2C_ACK();

       I2C_WriteByte(1);  //write address

       I2C_ACK();

       I2C_WriteByte(0x0a); //write data

       I2C_ACK();

       I2C_Stop();

       Delay1MS(10);

       I2C_Start();

       I2C_WriteByte(0xa0); //wirte device address

       I2C_ACK();

       I2C_WriteByte(1);   //wirte address for reading

       I2C_ACK();

       I2C_Stop();

       Delay1MS(2);

       I2C_Start();

       I2C_WriteByte(0xa1); //write device

       I2C_ACK();

       P2=I2C_ReadByte();//read data

       I2C_Stop();

       Delay1MS(50);

      while(1)；

}