并口模拟IIC的经验之谈（7） count

yuyang911220

void port2iicbase::i2c_stop()
{
SetPortVal(PORT1,0x07,1);/*scl 0, sda 1*/
delay(1);
SetPortVal(PORT1,0x0d,1);/*scl 1, sda 0*/
delay(1);/***/
SetPortVal(PORT1,0x0f,1);/*scl 1, sda 1*/
delay(1);/**/
SetPortVal(PORT1,0x05,1);/*scl 0, sda 0*/
}
/*************************************/
//函数名称：IIC 写一个字节函数
/*************************************/
int port2iicbase::i2c_writebyte(char c)
{
short int count=7;
char temp;
DWORD dwPortVal;
char e;while(count>=0)
{
   temp=c>>count;
   temp=temp<<7;          //确定传输的字节
   if (temp=='\x80')      //传输"1"
   {
    SetPortVal(PORT1,0x05,1);/*scl 0, sda 0*/
    delay(1);
    SetPortVal(PORT1,0x07,1);/*scl 0, sda 1*/
    delay(1);
    SetPortVal(PORT1,0x0f,1);/*scl 1, sda 1*/
    delay(1);
    SetPortVal(PORT1,0x07,1);/*scl 0, sda 1*/
    delay(1);
   }
   else                   //传输"0"
   {
    SetPortVal(PORT1,0x05,1);/*scl 0, sda 0*/
    delay(1);
    SetPortVal(PORT1,0x0d,1);/*scl 1, sda 0*/
    delay(1);
    SetPortVal(PORT1,0x05,1);/*scl 0, sda 0*/
    delay(1);
   }
   count--;
}
/**ask**/
SetPortVal(PORT1,0x07,1);/*scl 0, sda 1*/
delay(1);/***/
SetPortVal(PORT1,0x0f,1);/*scl 1, sda 1*/
delay(1);
// SetPortVal(PORT1,0x05,1);/*scl 0, sda 0*/
// delay(1);/***/
GetPortVal(PORT2, &dwPortVal, 1);
e = (char)dwPortVal;
temp=e>>4;
temp=temp<<7;
if (temp=='\x0')
   return 0;
else
   MessageBox(NULL,"Not Acknowledge!!","发送错误",MB_OKCANCEL);
return 1;
}