#include <avr/io.h>
#include "lcd-routines.h"
#include <util/delay.h>
#include <stdint.h>


void ADC_Init(void) {

  uint16_t result;

  ADMUX |= (1<<REFS1);
  ADMUX &= ~(1<<REFS0);

  ADCSRA = (1<<ADPS1) | (1<<ADPS0);
  ADCSRA |= (1<<ADEN);

  ADCSRA |= (1<<ADSC);
  while (ADCSRA & (1<<ADSC) ) {
  }
  result = ADCW;
}

uint16_t ADC_Read(uint8_t channel)
{
    ADMUX = (ADMUX & ~(0x1F)) | (channel & 0x1F);
    ADCSRA |= (1<<ADSC);
    while (ADCSRA & (1<<ADSC) ) {
    }
    return ADCW;
}

uint16_t ADC_Read_Avg(uint8_t channel, uint8_t nsamples)
{
  uint32_t sum = 0;

  for (uint8_t i = 0; i < nsamples; ++i) {
    sum += ADC_Read(channel);
  }

  return (uint16_t)(sum / nsamples);
}


int main(void)
{
    uint16_t adcval,wert;
    char val[100] = "";

    DDRD=(1<<DDD6)|(1<<DDD7);
    PORTD&=~(1<<PD6);
    lcd_init();
    ADC_Init();

    lcd_setcursor(0, 1);
    lcd_string("Spannung:");
    lcd_setcursor(0, 2);
    lcd_string("     mV");

    while(1)
    {
        adcval = ADC_Read_Avg(2, 10);  // Kanal 2, Mittelwert aus 4 Messungen
        adcval *= 5000;
        wert = 5000/1024;
        adcval *= wert;
        sprintf(val,"%d",adcval);
        lcd_setcursor(0, 2);
        lcd_string(val);
    }

    return 0;
}