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uchar SDA_Return(void)//0-low level 1-hign level
{
uchar flag;
uchar oldSREG=SREG;
SREG&=~(_BV(7));
DDRC&=0xfd;
PORTC|=_BV(PC1);
if((PINC&_BV(PC1)) !=0)//0000 0010
flag=1;
else
flag=0;
SREG=oldSREG;
return flag;
}
void delay(void)
{
;
;
}
void start(void)
{
SDA_1;
delay();
SCL_1;
delay();
SDA_0;
delay();
}
void stop(void)
{
SDA_0;
delay();
SCL_1;
delay();
SDA_1;
delay();
}
void respons(void)
{
uchar i=0;
SCL_1;
delay();
while((SDA_Return())&&(i<250))i++;
SCL_0;
delay();
}
void I2C_init(void)
{
SDA_1;
delay();
SCL_1;
delay();
}
void write_byte(unsigned char i)
{
unsigned char temp,num=0;
for(temp=0;temp<8;temp++)
{
num=i&0x80;
SCL_0;
delay();
if(num==0)
{SDA_0; }
else
{SDA_1; }
delay();
SCL_1;
delay();
i=i<<1;
delay();
}
SCL_0;
delay();
SDA_0;
delay();
}
uchar read_byte(void)
{
uchar i,j,value=0;
SCL_0;
for(i=0;i<8;i++)
{
value<<=1;
value|=SDA_Return();
SCL_1;
delay();
//delay();
SCL_0;
delay();
}
return value;
}
void Ack_I2c(void)
{
SDA_0;
delay();
SCL_1;
delay();
SCL_0;
delay();
SDA_1;
}
void NAck_I2c(void)
{
SDA_1;
delay();
SCL_1;
delay();
SCL_0;
delay();
}
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