const float gama = 0.7;
const float RL = 50;
void setup() {
  Serial.begin(9600);
}
void loop() {
  int analogValue = analogRead(A7);
  float voltage = analogValue / 1024. * 5;
  float resistance = 2000 * voltage / (1 - voltage / 5);
  float lux = pow(RL * 1e3 * pow(10, gama) / resistance, (1 / gama));
  if (analogRead(A1) >= 1){
    if (lux > 150){
      digitalWrite(8,1);
      tone(7, 250, 500);
      delay(500);
      digitalWrite(8,0);
      noTone(8);
      delay(500);
    }
  }
}