// MuTech Robotics - LP7 Automatic Street Light
// LDR module: AO -> A0, VCC -> 5V, GND -> GND  (higher reading = brighter; check yours in Serial Monitor)
// MOSFET module: SIG -> D9, GND -> GND, IN+ -> 12V, IN- -> GND, OUT+ / OUT- -> 12V LED lamp
// 12V adapter -> 12V rail -> Nano VIN and MOSFET IN+, all GNDs together
const int LDR = A0, LAMP = 9;
const int DARK = 300, BRIGHT = 450;   // two thresholds = no flicker at dusk
bool lampOn = false;

void setup() { pinMode(LAMP, OUTPUT); Serial.begin(9600); }

void loop() {
  long sum = 0;
  for (int i = 0; i < 10; i++) { sum += analogRead(LDR); delay(20); }
  int light = sum / 10;
  if (!lampOn && light < DARK) lampOn = true;        // getting dark: ON
  if (lampOn && light > BRIGHT) lampOn = false;      // daylight: OFF
  digitalWrite(LAMP, lampOn ? HIGH : LOW);
  Serial.print("Light: "); Serial.print(light); Serial.print("  Lamp: "); Serial.println(lampOn ? "ON" : "OFF");
  delay(300);
}