const char relay1 = 2;
const char relay2 = 3;
const char relay3 = 4;
const char relay4 = 5;
const char relay5 = 6;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(relay1, OUTPUT);
  Serial.println("Relay Ready!");
}

void loop() {
  // put your main code here, to run repeatedly:
  if (Serial.available()) {
    String command = Serial.readStringUntil('\n');
    if (command == "unlock_1") {
      digitalWrite(relay1, HIGH);
      Serial.println("1_unlocked");
      return;
    } else if (command == "lock_1") {
      digitalWrite(relay1, LOW);
      Serial.println("1_locked");
      return;
    }
    if (command == "unlock_2") {
      digitalWrite(relay2, HIGH);
      Serial.println("2_unlocked");
      return;
    } else if (command == "lock_2") {
      digitalWrite(relay2, LOW);
      Serial.println("2_locked");
      return;
    }
    if (command == "unlock_3") {
      digitalWrite(relay3, HIGH);
      Serial.println("3_unlocked");
      return;
    } else if (command == "lock_3") {
      digitalWrite(relay3, LOW);
      Serial.println("3_locked");
      return;
    }
    if (command == "unlock_4") {
      digitalWrite(relay4, HIGH);
      Serial.println("4_unlocked");
      return;
    } else if (command == "lock_4") {
      digitalWrite(relay4, LOW);
      Serial.println("4_locked");
      return;
    }
    if (command == "unlock_5") {
      digitalWrite(relay5, HIGH);
      Serial.println("5_unlocked");
      return;
    } else if (command == "lock_5") {
      digitalWrite(relay5, LOW);
      Serial.println("5_locked");
      return;
    }
  }
}