atmega 8+ analog to digital with proteus

[mshh]

I want to make analoge to digital on atmega8 using avrstudio i wrote code but wheen i simulate on proteus the Leds are always high and didn't change
please help

#ifndef F_CPU
#define F_CPU 8000000UL // or whatever may be your frequency
#endif

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

void adc_init(void)
{
	ADCSRA=0x85; //ENABLE ADC, PRESCALER 128
	ADMUX=0x00; 		//PC0, AVcc AS REFERENCE VOLTAGE
}

uint16_t adc_read()
{
	adc_init;
	while((ADCSRA)&(1<<ADSC)); 	//WAIT UNTIL CONVERSION IS COMPLETE
	return(ADC); 		//RETURN ADC VALUE
}

int main(void)
{
	
	uint16_t adc_value;
    DDRD=0xff;
	
	while(1)
	{
				
         adc_init(); 		//INITIALIZE ADC
		adc_value=adc_read(0); 		//READ ADC VALUE FROM CHANNEL 0
	    PORTD=ADC;
		
	}
}

 

[alexan_e]

post your schematic

- - - Updated - - -

ADCSRA=0x85; //ENABLE ADC, PRESCALER 128

That doesn't set the prescaler to 128 but 32

ADMUX=0x00; 		//PC0, AVcc AS REFERENCE VOLTAGE

Also a misleading comment, this sets the Vref to the voltage connected to AREF

I don't see anywhere the needed code to start a conversation, you only initialize the ADC over and over again.
You need to use

 // Start the AD conversion
    ADCSRA |= 0x40;

 

[mshh]

#ifndef F_CPU
#define F_CPU 8000000UL // or whatever may be your frequency
#endif

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

void adc_init(void)
{
	ADCSRA=0x85; //ENABLE ADC, PRESCALER 32
	ADMUX=0x00; 		//PC0, AVref AS REFERENCE VOLTAGE
}

uint16_t adc_read()
{
	adc_init;
	while((ADCSRA)&(1<<ADSC)); 	//WAIT UNTIL CONVERSION IS COMPLETE
	return(ADC); 		//RETURN ADC VALUE
}

int main(void)
{
	
	uint16_t adc_value;
    DDRD=0xff;
	
	while(1)
	{
				
         adc_init(); 		//INITIALIZE ADC
		  // Start the AD conversion
		  ADCSRA |= 0x40;
		adc_value=adc_read(0); 		//READ ADC VALUE FROM CHANNEL 0
	    PORTD=ADC;
		
	}
}

 

[alexan_e]

There is no point to call adc_init over and over again, just call it once at the start of main (out of the while loop) and you are done.

Also move DCSRA |= 0x40 inside adc_read

Your ADC result is stored in adc_value, why do you use PORTD=ADC ?

AVCC should also be connected to +5, that is the ADC supply

 

[mshh]

thanks it is working now