//Project : Dimmable LED using Buttons

int LEDpin=3;             //LED must be connected to PWM pins only(3,5,6,9,10,11)
int OnButtonPin=2;        //Buttons & Buzzer can be connected to any digital pin (1-13)
int OfButtonPin=4;
int BuzzerPin=5;

int LEDvalue=0;           // Stores current LED brightness value
int BuzzerTime=500;       //Buzzer ON time in milliseconds (1 second = 1000 milliseconds)
int delayTime=700;        //delayTime is used for smoother and better button control

void setup(){

  pinMode(OnButtonPin,INPUT);
  pinMode(OfButtonPin,INPUT);

  pinMode(LEDpin,OUTPUT);
  pinMode(BuzzerPin,OUTPUT);
}

void loop(){
  int OnButtonValue=digitalRead(OnButtonPin);
  int OfButtonValue=digitalRead(OfButtonPin);

  //Increase Brightness
  if (OnButtonValue==1){           //OnButtonValue==1 or OnButtonValue==0 change  according to pull down or pull up resistor 
    LEDvalue=LEDvalue+10;          //Brightness increase step
    if (LEDvalue>255){
      LEDvalue=255;                // 255 is the maximum LED brightness Value
      digitalWrite(BuzzerPin,HIGH);
      delay(BuzzerTime);}
    analogWrite(LEDpin,LEDvalue);}

  //Decrease Brightness  
  if (OfButtonValue==1){      
    LEDvalue=LEDvalue-10;           //Brightness decrease step
    if (LEDvalue<0){
      LEDvalue=0;                   // 0 is the minimum LED brightnessvalue( LED is OFF)
      digitalWrite(BuzzerPin,HIGH);
      delay(BuzzerTime);}
    analogWrite(LEDpin,LEDvalue);}

  delay(delayTime);
  digitalWrite(BuzzerPin,LOW);        //Turn OFF buzzer
}