24c02-4.c

ts1620液晶的驱动 24c02 红外遥控器 1302的驱动

/*     51系列单片机在使用时，有时需要模拟I2C总线，                      */
/*   这里举出一个实例（读写串行EEPROM芯片at2402）                       */
/************************************************************************/
/* Name:AT24C02存储器的读写程序,用到I2C总线,含相对独立的I2C总线读写函数 */
/* Language: C51单片机编程语言                                          */
/* Platform: Win98,Intel Celeron 433 Processor,伟福仿真器，仿真8751     */
/* Author:  StephenZhu    [e-mail]                               */
/* Date: 2003年5月21日,5月22日,5月29日                                  */
/* Version: 1.1.1                            */
/* Others: None 
//写与读之间要有足够的时间                                                        */
/************************************************************************/

    #include<string.h>
    #include <REGX51.H>
    #include<intrins.h>
    #define uchar unsigned char
    #define DELAY_TIME 8 /*经实验，不要小于50！否则可能造成时序混乱*/
    #define TRUE 1
    #define FALSE 0
    sbit Wp=P3^6;
    sbit SCL=P3^5;/*假设由P1.7和P1.6控制*/
    sbit SDA=P3^4;
uchar dispbuf[8]={1,1,0,0,0,0,0,0};
uchar dispbitcnt=0;
int dispbit;
    uchar  i;
void display (unsigned char * dispbuf)
  {  uchar dispbit;
    P2=dispbuf[dispbitcnt];
    dispbit=dispbitcnt;
   	dispbit<<=4;
	P2|=dispbit;
	dispbitcnt++;
   if(dispbitcnt==8)
     dispbitcnt=0;
   
  }


/********** Function Definition　函数定义 ************/

    void DELAY(unsigned int t) /*延时函数*/
    {
        while(t!=0)
            t--; 
    }

    void I2C_Start(void)
    {
        /*启动I2C总线的函数，当SCL为高电平时使SDA产生一个负跳变*/
        SDA=1;
        SCL=1;
        DELAY(DELAY_TIME);
        SDA=0;
        DELAY(DELAY_TIME);
        SCL=0;
        DELAY(DELAY_TIME);
    }

    void I2C_Stop(void)
    {
        /*终止I2C总线，当SCL为高电平时使SDA产生一个正跳变*/
        SDA=0;
        SCL=1;
        DELAY(DELAY_TIME);
        SDA=1;
        DELAY(DELAY_TIME);
        SCL=0;
        DELAY(DELAY_TIME);
    }

    void SEND_0(void)   /* SEND ACK */
    {
        /*发送0，在SCL为高电平时使SDA信号为低*/
        SDA=0;
        SCL=1;
        DELAY(DELAY_TIME);
        SCL=0;
        DELAY(DELAY_TIME);
    }

    void SEND_1(void)
    {
        /*发送1，在SCL为高电平时使SDA信号为高*/
        SDA=1;
        SCL=1;
        DELAY(DELAY_TIME);
        SCL=0;
        DELAY(DELAY_TIME);
    }

    bit Check_Acknowledge(void)
    {
        /*发送完一个字节后检验设备的应答信号*/
        SDA=1;
        SCL=1;
        DELAY(DELAY_TIME/2);
        F0=SDA;
        DELAY(DELAY_TIME/2);
        SCL=0;
       
        if(F0==1)
           { DELAY(DELAY_TIME); 
            return FALSE;
            }
     return TRUE;
    }

    void WriteI2CByte(uchar b)//reentrant
    {
        /*向I2C总线写一个字节*/
        uchar i;
        for(i=0;i<8;i++)
            if((b<<i)&0x80)
                {SEND_1();
                 }
            else
                SEND_0();
    }

 

    uchar ReadI2CByte(void)//reentrant
    {
        /*从I2C总线读一个字节*/
        uchar b=0,i;
        for(i=0;i<8;i++)
        {
            SDA=1;    /*释放总线*/
            SCL=1;    /*接受数据*/
            DELAY(10);
            F0=SDA;
           DELAY(10);
            SCL=0;
            if(F0)
                {
                    b=b<<1;
                    b=b|0x01;
                 }
           else
                b=b<<1;
        } 
                
        return b;
    }


/**********以下为读写24c02的函数**********/
void Write_One_Byte(char addr,uchar thedata)
{
          bit acktemp=1;
          /*write a byte to mem*/
          I2C_Start();   
          WriteI2CByte(0xa0); 
          acktemp=Check_Acknowledge();
          WriteI2CByte(addr);/*address*/
          acktemp=Check_Acknowledge();
          WriteI2CByte(thedata);/*thedata*/
          acktemp=Check_Acknowledge();
          I2C_Stop();

}

void Write_A_Page(uchar *buffer,char addr)
{
          bit acktemp=1;
          bit wrtmp;
          int i;
          /*write a page to at24c02*/
          I2C_Start();
          WriteI2CByte(0xa0);
          acktemp=Check_Acknowledge();
          WriteI2CByte(addr);/*address*/
          acktemp=Check_Acknowledge();
          for(i=0;i<7;i++)
          {
            WriteI2CByte(buffer[i]);
            if(!Check_Acknowledge())
                {
                    I2C_Stop();

                }
           }


          I2C_Stop();

 


}

uchar Read_One_Byte(char addr)
{         bit acktemp=1;
          uchar mydata;
           /*read a byte from mem*/
          I2C_Start();
          WriteI2CByte(0xa0);
          acktemp=Check_Acknowledge();
          WriteI2CByte(addr);/*address*/
          acktemp=Check_Acknowledge();
          I2C_Start();
          WriteI2CByte(0xa1);
          acktemp=Check_Acknowledge();
           mydata=ReadI2CByte();
    
           SEND_1();  I2C_Stop();
          return mydata;
         
}

void Read_N_Bytes(char *buffer,char n,char addr)
{
          bit acktemp=1;

          int i=0;
           /*read 8 bytes from mem*/
          I2C_Start();
          WriteI2CByte(0xa0);
          acktemp=Check_Acknowledge();
         
          WriteI2CByte(addr);/*address*/
          acktemp=Check_Acknowledge();
          I2C_Start();
          WriteI2CByte(0xa1);

          acktemp=Check_Acknowledge();

 


          for(i=0;i<n;i++)
          {
                buffer[i]=ReadI2CByte();
                if(i!=n-1)
                    SEND_0();    /*发送应答*/
                else
                    SEND_1();    /*发送非应答*/
          }

   I2C_Stop();

}


void main()
{
          int i;
          uchar mybyte;
          uchar myarray[8];
          uchar myarray2[8];
          uchar rdarray[16];   long      cunt=1000;  
        P2=0xff;
        Wp=0;
 
          for(i=0;i<8;i++)
          {
                myarray[i]=i;
                myarray2[i]=i+0x08;     

          }
          Write_One_Byte(0x20,0x22);
          DELAY(100); 
         mybyte=Read_One_Byte(0x20);
          dispbuf[4]=mybyte%10;
          dispbuf[5]=mybyte/10;
          while(1)
            {display(dispbuf);
             DELAY(100);
              DELAY(100);  }
              //   DELAY(10);   
          //Read_N_Bytes(rdarray,16,0x10);

}