inverter_mono.ino

#include "TimerOne.h"
#define PI 3.14159
#define SIZE 50
const float increment = PI / SIZE;
int dregreePhase = 360;
int delayDegree = 90;
float radiansPhase, radiansAux;

float calcRadians(int degree) {
  return (float) degree * (PI / 180);
}
unsigned int counter = 0;
void setFrequency(int freq) {
  Timer1.initialize(1000000 / (freq * SIZE));
}
void interruption(){
  static uint8_t pwm = 0x00;
  static bool up = true;
  
  float x = counter * increment;
  OCR2A = (128 + 127 *sin(radiansPhase + x));
  OCR2B = (128 + 127 *sin(radiansAux + x));
  counter = (counter + 1) % (SIZE * 4);
}

void setup() {
  Timer1.attachInterrupt(interruption);
  radiansPhase = calcRadians(dregreePhase);
  radiansAux = calcRadians(dregreePhase - delayDegree);

  DDRB = (1 << PB3);
  DDRB |= (1 << PB5);
  DDRD = (1 << PD3);
  setFrequency(1);
  
  TCCR2A = 1 << COM2A1 | 1 << COM2B1 | 1 << WGM21 | 1 << WGM20;
  TCCR2B = 1 << CS20;
 
  sei();
   
}//end setup

void loop () {  
  static int f = 1;
  delay(1000);
  setFrequency(f++);
  f = f > 59?  1: f;
}