int pino_ldr = A1;
float luz;
int led = 2;

void setup() {
  // put your setup code here, to run once:
Serial.begin(115200);
pinMode(pino_ldr, INPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
luz = analogRead(pino_ldr);
Serial.println(luz);
delay(10);

if(luz >= 100) {
digitalWrite(2, HIGH);
}
  else (luz < 100); {
  digitalWrite(2, LOW);
}
}