Auto detect I2C slave device read/write address program

//=========================
//Project:     I2C device read/write address detect program
//Author:      Leo.Tseng
//Date:        2011/10/20
//MCU:         W78E054D
//CRYSTAL:     25Mhz
//Description: Use uart for input/output, set boudrate=9600,
//             auto detect I2C device read/write address.
//=========================
#include  <reg52.h>
#include  <stdio.h>

//副程式宣告
void I2C_START(void);
void I2C_STOP(void);
void I2C_CLOCK(int t);
void I2C_write(unsigned char I2C_DATA,int i);
void delay(unsigned int d);
int I2C_ACK(void);
void TIMER1_initinal(int boudrate);

sbit SDA = P2^0; //SDA
sbit SCL = P2^1; //SCL
//======================================
//主程式開始
void main(void)
{
 unsigned char uart_data[6];
 unsigned int data_buf[6]={0};
 int i=0;
 int index=0;
 int temp=0;
  unsigned char I2C_DATA=0xff;
  int device_ACK;
  unsigned int temp_buf;
    
  TIMER1_initinal(9600);                           // 使用UART,baudrate=9600
 
  printf("\nPress any key to start detect device I2C address!!");
  _getkey();                                       // 等待任何按鍵
  printf("\n\n");  
for (i=0;i<=I2C_DATA;i++)
{
 I2C_START();                                      // 開始I2C command
 
 delay(5);

 I2C_write(i,8);                                   // 寫入device address

 device_ACK=I2C_ACK();                             // 取得device ACK 狀態
 
 I2C_STOP();                                       // 停止I2C command

 if(device_ACK)                                    // 儲存 device ACK address
  {
   data_buf[index]=i;
//   printf("\nACK ADDRESS%d is %d",index,data_buf[index]);
   temp=index++;
  }
}
//index=0;
//===== Address轉換成字元顯示 ==========
 for(index=0;index<=temp;index++)                                  
  {
   if(data_buf[index]& 0x01)                                        //Read address 轉換
    {
     if (((data_buf[index]/16)>=10)&&((data_buf[index]/16)<=15))    //位址高半位元組是大於9?
      {
       temp_buf=data_buf[index]/16+0x37;                            //轉換成A~F
       uart_data[0]=(char)temp_buf;                                  
//       printf("\n11_Device Read address is %c\n",uart_data[0]);
      }
      else
       {
        temp_buf=data_buf[index]/16+0x30;                           //位址高半位元組小於等於9,轉換成0~9
       uart_data[0]=(char)temp_buf;                                  
//        printf("\n21_Device Read address is %c\n",uart_data[0]);
       }
     temp_buf=data_buf[index]%16+0x30;                              //位址低半位元組轉換成0~9
     uart_data[1]=(char)temp_buf;                                  
     printf("\nDevice Read address is 0x%c%c\n",uart_data[0],uart_data[1]);  
    }
    else                                                            //Write address 轉換
     {
       if (((data_buf[index]/16)>=10)&&((data_buf[index]/16)<=15))  //位址高半位元組是大於9?
        {
         temp_buf=data_buf[index]/16+0x37;                          //轉換成A~F
         uart_data[0]=(char)temp_buf;                     
        }
        else
         {
          temp_buf=data_buf[index]/16+0x30;                        //位址高半位元組小於等於9,轉換成0~9
         uart_data[0]=(char)temp_buf;                                      
         }
     temp_buf=data_buf[index]%16+0x30;                             //位址低半位元組轉換成0~9
     uart_data[1]=(char)temp_buf;                                  
     printf("\nDevice Write address is 0x%c%c\n",uart_data[0],uart_data[1]);  
    }
  }
}
//=======================================

//延時副程式
void delay(unsigned int d)
{  
 while (--d);
}

//I2C 開始副程式
//     ______
//SDA        \______
//     _________
//SCL           \_______
//         -| |-- START

void I2C_START(void)
{  
 if (SDA!=1) SDA=1;
 if (SCL!=1) SCL=1;
 delay(1);
 SDA = 0;
 delay(5);
 SCL = 0;
}

//I2C 停止副程式
//              _______
//SDA _________/
//           __________
//SCL ______/
//           -| |-- STOP
void I2C_STOP(void)
{  
 if (SDA!=0) SDA=0;
 if (SCL!=0) SCL=0;
 delay(1);
 SCL = 1;
 delay(4);
 SDA = 1;
 delay(10);
}

//I2C clock 產生副程式
void I2C_CLOCK(int t)
{
 delay(t);
 SCL = 1;      //設定SCL為高位準
 delay(t);
 SCL = 0;      //設定SCL為高位準
}

//I2C write 副程式
void I2C_write(unsigned char I2C_DATA,int i)
{
 //bit data_bit;
 while(i--)
   {
    SDA=(I2C_DATA & 0x80)? 1 : 0;  //取出最高位元,並送至SDA
    delay(1);                      //等待SDA穩定
    SCL = 1;
    delay(5);
    //I2C_CLOCK(5);
    I2C_DATA<<=1;                  //下個資料位元
    SCL = 0;
    //delay(1);
   }
}

//I2C ACK副程式
//          ___________ NO ACK
//SDA _____/ \_________ ACK
//           ____
//SCL ______/    \________
//        -|  b9  |---- ACK bit
int I2C_ACK(void)
{  
 SDA=1;
 delay(2);
 SCL=1;
 if(SDA==0)                     // 判斷ack bit是否拉low
  {
   delay(6);
   SCL = 0;
   return 1;                    // 是
  }
  else
   {
    delay(6);
    SCL = 0;
    return 0;                   // 否
   } 
 }

//UART副程式
void TIMER1_initinal(int boudrate)      
{
 PCON  = 0x00;                          // PCON: if SMOD=1(b7), Baud Rate is Doubled                         
 SCON  = 0x52;                          // SCON: mode 1, 8-bit UART, enable rcvr                   
 TMOD  = 0x20;                            // TMOD: timer 1, mode 2, 8-bit reload          
 //TH1   = 256-(11059200/384/boudrate);   // TH1:  reload value for baud @ 11.0592MHz, TH=0xFD
 TH1   = 256-(25000000/372/boudrate);     // TH1:  reload value for baud @ 25MHz, TH=0xF9   
 TR1   = 1;                               // TR1:  timer 1 run                             
 //TI    = 1;                             // TI:   set TI to send first char of UART   
}