#include <mega8.h>
#include <stdio.h>
#include <delay.h>
// Alphanumeric LCD Module functions
#asm
   .equ __lcd_port=0x12 ;PORTD
#endasm
#include <lcd.h>

#define FIRST_ADC_INPUT 0
#define LAST_ADC_INPUT 0
unsigned int adc_data[LAST_ADC_INPUT-FIRST_ADC_INPUT+1];
#define ADC_VREF_TYPE 0x40
float result;
 
// ADC interrupt service routine
// with auto input scanning
interrupt [ADC_INT] void adc_isr(void)
{
register static unsigned char input_index=0;
// Read the AD conversion result
adc_data[input_index]=ADCW;
// Select next ADC input
if (++input_index > (LAST_ADC_INPUT-FIRST_ADC_INPUT))
   input_index=0;
ADMUX=(FIRST_ADC_INPUT | (ADC_VREF_TYPE & 0xff))+input_index;
// Delay needed for the stabilization of the ADC input voltage
delay_us(10);
// Start the AD conversion
ADCSRA|=0x40;
}

void main(void)
{
char lcd_buffer[31];

// ADC initialization
// ADC Clock frequency: 125,000 kHz
// ADC Voltage Reference: AVCC pin
ADMUX=FIRST_ADC_INPUT | (ADC_VREF_TYPE & 0xff);
ADCSRA=0xCE;

lcd_init(8);
#asm("sei")
lcd_clear();
while (1)
      {
      
      lcd_gotoxy(0,0);
      result=((5.00*adc_data[0])/1024.00);
      sprintf(lcd_buffer,"U=%.2fV",result);
      lcd_puts(lcd_buffer);       

      };
}