int led = 3; 
int BUP = 11;
int BDN = 12;        
int val = 0;  
int fadeAmount = 5; 
void setup() {
  Serial.begin(115200);
  pinMode(led, OUTPUT);
  pinMode(BUP, INPUT);
  pinMode(BDN, INPUT);
}

void loop() {

//-----------------FADA1----------------------------------

//      val = val + fadeAmount;
//  if (val <= 0 || val >= 255) {fadeAmount = -fadeAmount;}

//   analogWrite(led, val);
//   delay(30);

//-----------------FADA2----------------------------------

 for(int val = 0; val <= 255; val++){Serial.println(val); analogWrite(led, val);delay(100); }
 for(int val = 255; val >= 0; val--){Serial.println(val); analogWrite(led, val);delay(100); }

//-----------------POT----------------------------------

//  val=analogRead(A0);
//  val=map(val,0,1023,0,255);
//   analogWrite(led, val);
//   Serial.println(val);

//-----------------BTN----------------------------------

// if(digitalRead(BUP) == HIGH && val < 255) { val += 50 ; Serial.println(val); analogWrite(led  , val); delay(500);}
// if(digitalRead(BDN) == HIGH && val >  0 ) { val -= 50 ; Serial.println(val); analogWrite(led  , val); delay(500);}
    
}