const int ledPin = 9;

int mode = 0;

int power = 0;

int input = 0;

int oldInput = 0;

unsigned long previousMillis = 0;

unsigned long currentMillis;

bool increasing = true;

void setup(){

  pinMode(ledPin, OUTPUT);
  Serial.begin(9600);

}

void loop(){

  oldInput = input;

  input = Serial.read();

  if(oldInput != input){
    if(input >= 50){
      mode = 0;
    }
    else if(input == 1){
      mode = 1;
    }
    else if(input == 2){
      mode = 2;
    }
    else{
      power = 0;
    }

    //power = 0;
  }

  currentMillis = millis();

  if(mode == 0){

    mode0();

  }
  else if(mode == 1){

    mode1();

  }
  else if(mode == 2){

    mode2();

  }

  analogWrite( 9, power);

}

void mode0(){ //power set to input from slider

  power = input;

}

void mode1(){ //slow increase then reset to zero cycle

  if(currentMillis - previousMillis >= 100){

      previousMillis = currentMillis;

      if(power <= 255){

        power += 5;

      }
      else{

        power = 0;

      }
    }
}

void mode2(){ //slow increase then decrease cycle

  if(currentMillis - previousMillis >= 100){

      previousMillis = currentMillis;

      if(power + 5 >= 255){

        increasing = false;

      }
      else if(power - 5 <= 45){

        increasing = true;

      }

      if(increasing && power + 5 < 255){

        power += 5;

      }
      else if(power - 5 > 45){

        power -= 5;

      }
    }

}

void mode3(){ //burst

  //if(currentMillis - previousMillis

}