int pinR=3;
int pinButton=A1;
void setup() {
  pinMode(pinR, OUTPUT);
  pinMode(pinButton, INPUT_PULLUP);
  // put your setup code here, to run once:

}

void loop() {
  int value=analogRead(pinButton);
  int ledValue=map(value,0,1023,0,255)
  analogWrite(pinR,ledValue);
  // put your main code here, to run repeatedly:

}