i2c.c

读卡器 fm1702实现收发 zlg7290实现按键与显示控制

#include "I2C.h"
#include <intrins.h>


void Delay(unsigned int t) // t ms
{ 
  unsigned int i,j;
  for(i=0;i<t;i++)
  {
     for(j=0;j<1000;j++)
	  _nop_();
   }
}
 
void I2C_Wait(void)
{
    _nop_(); _nop_(); _nop_(); _nop_(); _nop_();_nop_(); _nop_(); _nop_(); _nop_(); _nop_();_nop_(); _nop_(); _nop_(); _nop_(); _nop_();
}

void I2C_Start(void) //当SCL为高时，SDA由高到低，开始，然后SCL到低
{
     I2C_SDA = 1;
     I2C_SCL = 1;
     I2C_Wait();
     I2C_SDA = 0;
     I2C_Wait();
     I2C_SCL = 0;
}

void I2C_Stop(void) //当SCL为高时，SDA由低到高
{
     I2C_SDA = 0;
     I2C_Wait();
     I2C_SCL = 1;
     I2C_Wait();
     I2C_SDA = 1;
}

bit I2C_Send_Byte(uchar bytedata) 
{
     uchar data i;
     bit ack;

     for (i = 0; i < 8; i++)   
     {
         if (bytedata & 0x80) I2C_SDA = 1;
         else I2C_SDA = 0;
        
         bytedata <<= 1;
         I2C_Wait();

         I2C_SCL = 1;
         I2C_Wait();
         I2C_SCL = 0;
         I2C_Wait();
      }

          I2C_SDA = 1;   //发送器件释放SDA线
          I2C_Wait();
          I2C_SCL = 1;   //产生第九个脉冲的高电平
          I2C_Wait();
          ack = I2C_SDA;   //接收从器件的确认位
          I2C_SCL = 0;
          I2C_Wait();
          return ack;
}

uchar I2C_Receive_Byte(void)  
{
     uchar i;
     uchar bytedata = 0;
     for ( i = 0; i < 8; i++)
     {
         I2C_SCL = 1;
         I2C_Wait();

         bytedata <<= 1;
         if (I2C_SDA) bytedata |= 0x01; //若SDA=1，则将接收到的数据加1(bit0设为1)，否则但左移一位时就将bit0自动清0
        
         I2C_SCL = 0;
         I2C_Wait();
     }
     return bytedata;
}

void Send_Ack(bit ack) 
{
     I2C_SDA = ack;
     I2C_SCL = 1;
     I2C_Wait();
     I2C_SCL = 0;
}


void I2C_Byte_Write(uchar sla,uchar addr,uchar bytedata)
{   
     uchar data i;
     bit ack;

 //    Flag_Timeout = 1;

     for(i = 0; i < 10; i++)  
     {
         I2C_Start();
         ack = I2C_Send_Byte(sla);
         if (ack)
         {
                 I2C_Stop();
                 continue;
         }
  
         ack = I2C_Send_Byte(addr);
         if (ack)
         {
                 I2C_Stop();
                 continue;
         }

         ack = I2C_Send_Byte(bytedata);
         if (ack)
         {
                 I2C_Stop();
                 continue;
         }


         I2C_Stop();
      //   Flag_Timeout = 0;
         if(0 == ack) break;
     }
     Delay(10); //写入一个字节必须延迟10ms
}

uchar I2C_Byte_Read(uchar sla,uchar addr)
{   
     uchar bytedata;

     I2C_Start();
     I2C_Send_Byte(sla);
     I2C_Send_Byte(addr);
     I2C_Start();
     I2C_Send_Byte(sla+1);
     bytedata = I2C_Receive_Byte();
     Send_Ack(1);
     I2C_Stop();    
     return bytedata;
}
void I2C_Data_Write(uchar addr,uchar no,uchar *s)

{
    uchar data i,j;
    bit ack;

 //    Flag_Timeout = 1;

     for(i = 0; i < 10; i++)  
     {
         I2C_Start();
         ack = I2C_Send_Byte(ZLG7290);
         if (ack)
         {
                 I2C_Stop();
                 continue;
         }
  
         ack = I2C_Send_Byte(addr);
         if (ack)
         {
                 I2C_Stop();
                 continue;
         }

        for(j=0;j<no;j++)
        {
          ack=I2C_Send_Byte(*s); 
          if (ack)
          {
                 I2C_Stop();
                 continue;
          }
           s++;
        }
         I2C_Stop();
      //   Flag_Timeout = 0;
         if(0 == ack) break;
     }
     Delay(10); //写入一个字节必须延迟10ms
}

/*void I2C_Data_Read(uchar suba,uchar no,uchar *s)
{
   uchar data i,j;j=no;
   I2C_Start();               //启动总线
   I2C_Send_Byte(ZLG7290);            //发送器件地址
   I2C_Send_Byte(suba);            //发送器件子地址
   I2C_Start();
   I2C_Send_Byte(ZLG7290+1);
   for(i=0;i<j-1;i++)
    {
     *s++=I2C_Receive_Byte();            //接收数据
      Send_Ack(0);               //发送就答位
	  Delay(5);
    }
   *s=I2C_Receive_Byte();;
   Send_Ack(1);                 //发送非应位
   I2C_Stop();                    //结束总线

}	   */