float phi = 1;  // degrees
int uhol = 0;  // integer angle

int castprac1 = 1;  // duty cycle (from 0 to 2047 parts)
int castprac2 = 1;  // duty cycle (from 0 to 2047 parts)
int castprac3 = 1;  // duty cycle (from 0 to 2047 parts)

float frequencypwm = 1;

unsigned long past = 1;

float frekvenciavlny = 50;
float amplituda = 1;

unsigned long cas = 0;

float sinval[362];  // 10 stupňov na 1 hodnotu tejto "tabuľky"

float casvlny = 0;
float caspolvlny = 0;
float casvovlne = 0;
float castvlny = 0;

void setup() {

  pinMode(18, OUTPUT);
  pinMode(19, OUTPUT);
  pinMode(20, OUTPUT);
  pinMode(21, OUTPUT);
  pinMode(22, OUTPUT);
  pinMode(23, OUTPUT);

  byte anres = 11;  // bits // 2048 rôznych hodnôt

  Serial.begin(8000000);

  analogWriteResolution(18, anres);
  analogWriteResolution(19, anres);
  analogWriteResolution(20, anres);
  analogWriteResolution(21, anres);
  analogWriteResolution(22, anres);
  analogWriteResolution(23, anres);

  frequencypwm = 10000;  // Hz

  analogWriteFrequency(18, frequencypwm);
  analogWriteFrequency(19, frequencypwm);
  analogWriteFrequency(20, frequencypwm);
  analogWriteFrequency(21, frequencypwm);
  analogWriteFrequency(22, frequencypwm);
  analogWriteFrequency(23, frequencypwm);

  for (int i = 0; i < 361; i = i + 1) {
    int z = i * 1;
    double radiany = (((double)z * 71.0) / 4068.0);
    sinval[i] = 2047 * (abs(sin(radiany)));
    Serial.println(sinval[i]);
  }
}

void loop() {

  cas = micros();

  if (Serial.available() > 2) {
    frekvenciavlny = Serial.parseFloat();
    amplituda = Serial.parseFloat();
    Serial.println(frekvenciavlny);
    Serial.println(amplituda);
  }

  //frekvenciavlny = analogRead(A0) / 4;

Serial.println(micros());

  casvlny = 1000000.0 / (float)frekvenciavlny;
  caspolvlny = (float)casvlny / 2.0;
  casvovlne = fmod(cas, casvlny);
  castvlny = ((float)casvovlne / (float)casvlny);

  phi = 360.0 * castvlny;
  phi = fmod(phi, 360.0);

  uhol = int(phi);

  castprac1 = amplituda * sinval[uhol];
  castprac2 = amplituda * sinval[((uhol + 120) % 360)];
  castprac3 = amplituda * sinval[((uhol + 240) % 360)];

  if (uhol < 180) {
    analogWrite(18, castprac1);
    analogWrite(19, 0);
  } else {
    analogWrite(18, 0);
    analogWrite(19, castprac1);
  }

  if (((uhol + 120) % 360) < 180) {
    analogWrite(20, castprac2);
    analogWrite(21, 0);
  } else {
    analogWrite(20, 0);
    analogWrite(21, castprac2);
  }

  if (((uhol + 240) % 360) < 180) {
    analogWrite(22, castprac3);
    analogWrite(23, 0);
  } else {
    analogWrite(22, 0);
    analogWrite(23, castprac3);
  }
}