void setup() {
  Serial.begin(9600);

  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(0, INPUT);
}

void loop() {

  float potent = analogRead(0);
  float mapping = map(potent,0,1023,0,100); 
  digitalWrite(2, HIGH);     
  Serial.print(mapping);
  Serial.println("%"); 
  analogWrite(3, potent);         


}