const int pinfov = 10;
const int pinrev = 11;
const int buttadd = 12;
const int buttdec = 13;
int runtime = 1000;
int runperc = 30;
int x;
static unsigned long prev_time, time, lastbutt, period = 0;
bool dir = true;
bool run = false;

void setup()
{
  Serial.begin(9600);

  pinMode(pinfov, OUTPUT);
  pinMode(pinrev, OUTPUT);
  pinMode(buttadd, INPUT);
  pinMode(buttdec, INPUT);

  time = micros()/1000;
  prev_time = time;

  digitalWrite(pinrev, LOW);
  digitalWrite(pinfov, HIGH);

  x = runtime/200*runperc;

  while (period < x) {
    time = micros();
    period = time - prev_time;
  }

  digitalWrite(pinfov, LOW);
  digitalWrite(pinrev, LOW);

  time = micros()/1000;
  prev_time = time;
}

void loop()
{
  time = micros()/1000;
  period = abs(time - prev_time);

  if (abs(time-lastbutt)>100) {
    lastbutt=time;
    if (digitalRead(buttadd)==HIGH and runperc<100) {
      runperc += 10;
      Serial.println("+ PRESSED");
    }
    if (digitalRead(buttdec)==HIGH and runperc>10) {
      runperc -= 10;
      Serial.println("- PRESSED");
    }
  }

  if (period>runtime){
    prev_time = time;
    dir = !dir;
    run = false;
  }
  if (period % 10 < 1) {
   x = runtime/100*runperc;
  if (period < x) {
    if (dir and !run) {
      digitalWrite(pinfov, LOW);
      digitalWrite(pinrev, HIGH);
      Serial.print("REV: ");
      Serial.println(x);
      run = true;
    } else if (!run) {
      digitalWrite(pinrev, LOW);
      digitalWrite(pinfov, HIGH);
      Serial.print("FOV: ");
      Serial.println(x);
      run = true;
    }
  } else if (run) {
    digitalWrite(pinfov, LOW);
    digitalWrite(pinrev, LOW);
    Serial.print("STOP: ");
    Serial.println(runtime - x);
    run = false;
  } }
delay (10);
}