#define Buzzer_Pin 5
#define Blue_Btn 1
#define Red_Btn 2
#define Yellow_Btn 3
#define Green_Btn 4
#define LEDPIN1 14
#define LEDPIN2 15
#define LEDPIN3 16

int Led1State = !Led1State;
int BuzzerState = !BuzzerState;


int led_delay = 800;
int led_voltage = LOW; //LOW
int last_changed = 0;

int rbt = 0, rbt_past = 0;
int ybt = 0, ybt_past = 0;

int brightness = 0;
int fadeAmount = 5;

void setup() {
  // put your setup code here, to run once:
  pinMode(Buzzer_Pin, OUTPUT);
  pinMode(Blue_Btn, INPUT_PULLUP);
  pinMode(Red_Btn, INPUT_PULLUP);
  pinMode(Yellow_Btn, INPUT_PULLUP);
  pinMode(Green_Btn, INPUT_PULLUP);
  pinMode(LEDPIN1, OUTPUT);
  pinMode(LEDPIN2, OUTPUT);
  pinMode(LEDPIN3, OUTPUT);
  
  analogWrite(LEDPIN3, OUTPUT);
}

void loop() {


  
  // put your main code here, to run repeatedly:

  // 3 led will be on when all of the digitalwrite Led functions will be high;
    // digitalWrite(Led1, HIGH);
    //delay(100);
    //digitalWrite(Led1, LOW);
    //delay(1000);(Repeat for 3 led)

  // 3 led will blink one after another when digitalwrite Led functions will be high and low with time delay;

  // C1: Press Push Blue_Btn and led will be on, it won't stop even if you press the button again.
    //int PushBlue = digitalRead(Blue_Btn);
    //if (PushBlue == HIGH){
    //digitalWrite(Led1, HIGH);
  
  // C1: led will blink after pressing the btn
    //int PushBlue = digitalRead(Blue_Btn);     
    //if (PushBlue == HIGH){
    //digitalWrite(Led1, HIGH);
    //delay(100);
    //digitalWrite(Led1, LOW);
    //delay(1000);

    // C2: Led will be on after running the code and when press the push botton it will be off.
      //if (digitalRead(Blue_Btn) == HIGH){
      //digitalWrite(Led1, HIGH );
      //digitalWrite(Led1, LOW);
      //digitalWrite(Buzzer_Pin, HIGH);
      //delay(50);

      if (digitalRead(Blue_Btn) == LOW){

        Led1State = !Led1State;
        BuzzerState = !BuzzerState;

      digitalWrite(LEDPIN1, Led1State);
      delay(100);
      

      digitalWrite(Buzzer_Pin, BuzzerState);
      delay(100);
      
    } 
    if (millis() >= last_changed + led_delay){
    led_voltage = !led_voltage;
    digitalWrite(15, led_voltage);
    last_changed = millis();
    }
      

    rbt_past = rbt;
    rbt = digitalRead(Red_Btn);
    if (rbt == LOW && rbt_past == HIGH){
       led_delay -= 400;
    }

    ybt_past = ybt;
    ybt = digitalRead(Yellow_Btn);
    if (ybt == LOW && ybt_past == HIGH){
       led_delay += 400;
    }

   delay(50);
  if (digitalRead(Green_Btn) == LOW) {
    if (brightness == 0) {
      brightness = 255;
    } else {
      brightness = 0;
    }
    analogWrite(LEDPIN3, brightness);
    delay(100);
  }  
}