// Relay control via NPN Transistor (2N3904)
// Amaliy ish 3: Tranzistor orqali relay boshqaruvi
// Arduino Pin 7 -> 1kOhm rezistor -> Tranzistor baza

const int transistorPin = 7;  // Tranzistor baza pini

void setup() {
  pinMode(transistorPin, OUTPUT);
  Serial.begin(9600);
  Serial.println("Relay va Tranzistor loyihasi boshlandi!");
}

void loop() {
  // Relay YOQISH - tranzistor ochiq, relay coil energiyalanadi
  digitalWrite(transistorPin, HIGH);
  Serial.println("Relay ON - LED yondi");
  delay(1000);

  // Relay O'CHIRISH - tranzistor yopiq, relay coil de-energiyalanadi
  digitalWrite(transistorPin, LOW);
  Serial.println("Relay OFF - LED o'chdi");
  delay(1000);
}