int LedPinA = 5;



int LedPinB = 6;



int ButtonPinA = 7;



int ButtonPinB = 4;



int buttonStateA = 0; 



int buttonStateB = 0;



int brightness   = 0;



 



void setup() 



{



    pinMode(LedPinA, OUTPUT); 



    pinMode(LedPinB, OUTPUT);  



    pinMode(ButtonPinA, INPUT); 



    pinMode(ButtonPinB, INPUT);     



}



 



void loop() 



{



  buttonStateA = digitalRead(ButtonPinA);



  if (buttonStateA == HIGH && brightness != 255)



  { 



   brightness ++;



  } 



 



   buttonStateB = digitalRead(ButtonPinB);



   if (buttonStateB == HIGH && brightness != 0)



  { 



   brightness --;



  } 



      analogWrite(LedPinA, brightness);  //  A will turn off gradually 



      analogWrite(LedPinB, 255 - brightness);  // B will turn on gradually 



      delay(25);



}