74164.c

An algorithm I2C communication as a master in AVR MCU using WINCC

//*******************************************/
//Standard function for ouputing LED         / 
//Copyright of BKCTM1  2009                  /
//*******************************************/

void out_74164(char data)        
{
char temp; 
char i;
DDRD |=0xC0;
PORTD &=0x3F;          
for(i=7;i<8;i--)
 {
CLK=low; 
temp=data>>i;
PORTD.6 = temp & 0x01;
CLK=high;// making a rising edge              
 }
} 

void out_led(char *N)
{
switch(*N)
{
case 1:
    out_74164((LED%10) |(0xE0));
    break;
case 2:
    out_74164((LED/10%10) |(0xD0));
    break;
case 3:
    out_74164((LED/100%10) |(0xB0));
    break;
case 4:
    out_74164((LED/1000%10) |(0x70));
    *N=0;
    break;     
 }
}