/*    ATmega48, тактирование внутреннее 8 MHz*/

//#define F_CPU 8000000

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

#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>

void set_pwm(unsigned char, unsigned char, unsigned char);
int adc_convert(unsigned char);

unsigned int max=1, min=1, average=0;
double factor=0;
unsigned char abc = 0;

ISR(TIMER1_OVF_vect){
  unsigned int input;
  
  input = adc_convert(0);
  if (input > max) max = input;
  
  factor = (double)input/(double)max
  
  OCR0A =  (unsigned char)(0xFF * factor);

  TCNT1 = 65503;                                    // 4mS
}

// ********************  ADC   *****************************

void adc_init(void){
  ADMUX = (0<<REFS1)|(1<<REFS0);                                        // AVCC - 5v
  ADCSRA = (1<<ADEN)|(1<<ADPS2)|(1<<ADPS1)|(1<<ADPS0);                // CK/128
  //ADCSRB = (1<<ADTS2)|(1<<ADTS1)|(0<<ADTS0);                          // timer1 overflow
}

int adc_convert(unsigned char channel){
  unsigned int result;
  
  ADMUX = (ADMUX & 0xF0)|channel;
  ADCSRA |= (1<<ADSC);

  while (!(ADCSRA & (1<<ADSC)));
  
  
  result = ( ((int)ADCH << 8) | (int)ADCL);
  return result;
}



// ********************  PWM   *****************************

void pwm_init(void){
  // Timer0 init
  DDRD |= (1<<PD5)|(1<<PD6);
  TCCR0A |= (1<<COM0A1)|(1<<COM0B1)|(1<<WGM01)|(1<<WGM00);        // Fast PWM
  TCCR0B |= (1<<CS00);                                                // CK/1, F pwm =
  
  // Timer2 init
  DDRB |= (1<<PB3);
  TCCR2A |= (1<<COM2A1)|(1<<WGM21)|(1<<WGM20);                    // Fast PWM
  TCCR2B |= (1<<CS20);                                                // CK/1, F pwm =
}

void set_pwm(unsigned char r, unsigned char g, unsigned char b){
  OCR0A = r;
  OCR0B = g;
  OCR2A = b;
}

void timer1_init(void){
  TCCR1B |= (1<<CS12)|(0<<CS11)|(1<CS10);            // step = 1/8mS
  TIMSK1 |= (1<<TOIE1);                            // int. ovf. enable
  TCNT1 = 65505;                                    // 1000mS
}


int main (void) {
  adc_init();
  pwm_init();                                        // timers 0 & 2 init
  timer1_init();
  
  sei();
  while(1);
}

  result = ADC;