IOT

🔑 Arduino Password System with Buzzer Alert

A simple Arduino project that checks a password via Serial Monitor and alerts with a buzzer if incorrect.

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📌 Code

int buzzerPin = 10;
String password = "1234";
String inputPassword = "";

void setup() {
  pinMode(buzzerPin, OUTPUT);
  Serial.begin(9600);
  Serial.println("Enter password:");
}

void loop() {
  if (Serial.available()) {
    inputPassword = Serial.readStringUntil('\n');
    inputPassword.trim();

    if (inputPassword == password) {
      Serial.println("Access Granted");
    } else {
      Serial.println("Wrong Password!");
      wrongPasswordBeep();
    }
  }
}

void wrongPasswordBeep() {
  for (int i = 0; i < 3; i++) {
    digitalWrite(buzzerPin, HIGH);
    delay(200);
    digitalWrite(buzzerPin, LOW);
    delay(200);
  }
}

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📖 Explanation

1. Variable Setup

• buzzerPin → Pin number where the buzzer is connected.
• password → The fixed correct password ("1234").
• inputPassword → Stores user input from Serial Monitor.

2. setup() Function

• Configures buzzer pin as output.
• Starts serial communication at 9600 baud.
• Prompts user to enter a password.

3. loop() Function

• Checks if user typed something in Serial Monitor.
• Reads input until newline (\n).
• Compares entered password with correct one:
  • If correct → prints "Access Granted".
  • If wrong → prints "Wrong Password!" and calls buzzer function.

4. wrongPasswordBeep() Function

• Makes buzzer beep 3 times when password is incorrect.
• Each beep lasts 200 ms followed by 200 ms silence.

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⚙️ Summary

This project is a simple password-protected system using Arduino:

• User enters a password via Serial Monitor.
• If correct → Access granted.
• If wrong → Buzzer beeps 3 times as an alert.

💡 Great for beginners learning Arduino input/output and security basics!