float ledval;
int potval;
int dt=1000;
int readval=A2;
int readpin=9;

void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
pinMode(readpin,OUTPUT);
pinMode(readval, INPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
potval=analogRead(readval);
ledval=(255./1023.)*potval;
analogWrite(readpin,ledval);
Serial.println(ledval);
}