#define ldr 4
#define led 13
void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(ldr, INPUT);
  pinMode(led, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  delay(10); // this speeds up the simulation
  float ldrValue = analogRead(ldr);
  float brightness = map(ldrValue, 0, 4095, 0, 255);
  analogWrite(led, brightness);
}