int readtime=250;//delay 250 millisecond to execute next loop 
const int LedPin=9;
const int PotOut=A2;
unsigned int PotVal;//output of potentiometer in range of 0-1023
float Ledval;
float BrightPercentage;
void setup() {
  // put your setup code here, to run once:
  pinMode(PotOut, INPUT);//declaring the  input pin
  Serial.begin(9600);//start the serial communication

}

void loop() {
  // put your main code here, to run repeatedly:
  
  PotVal=analogRead(PotOut);//read the output of potentiometer
  Ledval=(255./1023.)*PotVal; // calibrate the value of led according to potentiometer
  analogWrite(LedPin,Ledval);//using pwm pin to write analog data 
  BrightPercentage=(100./255.)*Ledval;
  Serial.print("The brightness in percentage is: ");
  Serial.println(BrightPercentage);
  delay(readtime);//delay the execution of next loop
}