const int sensorPin =0;
const int ledPin = 9;

void setup() {
  // put your setup code here, to run once:
  pinMode(ledPin,OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
 int value = analogRead(sensorPin);
 int intensity = map(value,0,1023,0,255);
 analogWrite(ledPin,intensity);
}