Pattern Lock Using Touch Sensor

// www.matthewtechub.com
// Touch sensor password with LED and buzzer

const int touchPins[] = {2, 3, 4}; // Pins connected to the touch sensors
const int buttonPin = 5;           // Pin connected to the button switch
const int ledPin = 6;              // Pin connected to the LED
const int buzzerPin = 7;           // Pin connected to the buzzer

const int password[] = {3, 1, 2};  // The password sequence (touch sensor 3, then 1, then 2)
const int passwordLength = 3;      // Length of the password

int inputSequence[passwordLength]; // Array to store the input sequence
int inputIndex = 0;                // Index to track input sequence

void setup() {
  Serial.begin(9600);              // Initialize serial communication
  for (int i = 0; i < 3; i++) {
    pinMode(touchPins[i], INPUT);  // Set touch pins as inputs
  }
  pinMode(buttonPin, INPUT_PULLUP); // Set button pin as input with internal pull-up resistor
  pinMode(ledPin, OUTPUT);         // Set LED pin as output
  pinMode(buzzerPin, OUTPUT);      // Set buzzer pin as output

  digitalWrite(ledPin, LOW);       // Ensure LED is initially off
  digitalWrite(buzzerPin, LOW);    // Ensure buzzer is initially off
}

void loop() {
  if (digitalRead(buttonPin) == LOW) { // Check if the button is pressed
    delay(50); // Debounce delay
    while (digitalRead(buttonPin) == LOW); // Wait for button release

    inputIndex = 0; // Reset input sequence index
    Serial.println("Enter password sequence:");

    // Wait for password input
    while (inputIndex < passwordLength) {
      for (int i = 0; i < 3; i++) {
        if (digitalRead(touchPins[i]) == HIGH) {
          inputSequence[inputIndex] = i + 1; // Store the touch sensor number (1, 2, 3)
          inputIndex++;
          Serial.print("Touch sensor ");
          Serial.println(i + 1);
          delay(500); // Debounce delay
          while (digitalRead(touchPins[i]) == HIGH); // Wait for sensor release
        }
      }
    }

    // Check if the entered sequence matches the password
    bool isCorrect = true;
    for (int i = 0; i < passwordLength; i++) {
      if (inputSequence[i] != password[i]) {
        isCorrect = false;
        break;
      }
    }

    if (isCorrect) {
      digitalWrite(ledPin, HIGH); // Turn on the LED if password is correct
      Serial.println("Password correct!");
    } else {
      digitalWrite(buzzerPin, HIGH); // Turn on the buzzer if password is incorrect
      Serial.println("Password incorrect!");
      delay(5000); // Buzzer on for 1 second
      digitalWrite(buzzerPin, LOW);
    }

    delay(5000); // Wait 3 seconds before resetting
    digitalWrite(ledPin, LOW); // Turn off the LED
    Serial.println("Ready for new input.");
  }
}