ADC ATmega 32 dengan AVRStudio 4.19

#include <avr/io.h>
#include <util/delay.h>

#define ADC_VREF_TYPE 0x60

unsigned char buffer=0;

// Read the 8 most significant bits
// of the AD conversion result


unsigned char read_adc(unsigned char adc_input)
{
ADMUX=(adc_input & 0x07) | (ADC_VREF_TYPE & 0xff);

_delay_us(10);
// Start the AD conversion
ADCSRA|=0x40;
// Wait for the AD conversion to complete
while ((ADCSRA & 0x10)==0);
ADCSRA|=0x10;
return ADCH;
}

int main (void)
{
DDRA=0b00000000;
PORTA=0b00000000;

// ADC initialization
// ADC Clock frequency: 1000.000 kHz
// ADC Voltage Reference: AVCC pin
// ADC Auto Trigger Source: None
// Only the 8 most significant bits of
// the AD conversion result are used
ADMUX=ADC_VREF_TYPE & 0xff;
ADCSRA=0x83;

while(1)
    {
    buffer=read_adc(0);
    if(buffer<127){DDRC=1;PORTC=1;}
    else if(buffer>127){DDRC=1;PORTC=0;}
    }
}

semoga bermanfaat