#include <Keypad.
h>
#include <Servo.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
// Pin configuration for the 4x4 keypad
const byte ROW_NUM = 4; // Four rows
const byte COLUMN_NUM = 4; // Four columns
char keys[ROW_NUM][COLUMN_NUM] = {
{'1','2','3','A'},
{'4','5','6','B'},
{'7','8','9','C'},
{'*','0','#','D'}
};
// Pin assignments for the keypad
byte pin_rows[ROW_NUM] = {9, 8, 7, 6}; // Connect to the row pinouts of
the keypad
byte pin_column[COLUMN_NUM] = {5, 4, 3, 2}; // Connect to the column
pinouts of the keypad
// Create keypad object
Keypad keypad = Keypad(makeKeymap(keys), pin_rows, pin_column,
ROW_NUM, COLUMN_NUM);
// Create Servo object
Servo myServo;
// Create LCD object (Address 0x27, 16x2 LCD display)
LiquidCrystal_I2C lcd(0x27, 16, 2);
// Variables for servo control
bool servoOpen = false; // Track if the servo is open or closed
char sequence[3]; // Store the last 3 keys pressed
byte seqIndex = 0; // Index to track sequence position
// Timer for inactivity (e.g., 5 seconds of inactivity before closing the servo)
unsigned long lastKeyPressTime = 0; // Track the last key press time
const unsigned long INACTIVITY_TIMEOUT = 5000; // 5 seconds
// Password to open the servo (as "123")
const char password[] = "123";
byte passwordLength = 3; // Length of the password
void setup() {
// Attach the servo to pin 9
myServo.attach(9);
// Initialize the servo to the closed position
myServo.write(0); // 0 degrees is the closed position
// Start Serial communication for debugging
Serial.begin(9600);
// Initialize LCD
lcd.begin(16, 2); // Initialize the LCD
lcd.setBacklight(1); // Turn on the backlight
// Show initial message
lcd.clear();
lcd.print("Enter the password");
void loop() {
// Read the pressed key
char key = keypad.getKey();
// Check if a key was pressed
if (key) {
Serial.println(key); // For debugging purposes, print the key pressed
// Update the last key press time
lastKeyPressTime = millis();
// If we haven't yet reached the length of the password sequence
if (seqIndex < passwordLength) {
sequence[seqIndex] = key; // Store the key in the sequence
seqIndex++; // Increment the sequence index
// Check if the sequence has reached the password length (3 digits)
if (seqIndex == passwordLength) {
// Compare the entered sequence with the password
if (strncmp(sequence, password, passwordLength) == 0) {
// Correct password entered, open the servo
if (!servoOpen) {
myServo.write(90); // 90 degrees is the open position
servoOpen = true;
lcd.clear();
lcd.print("Access Granted");
Serial.println("Correct password! Servo opened.");
} else {
// Incorrect password, reset the sequence
seqIndex = 0; // Reset the sequence index
lcd.clear();
lcd.print("Access Declined");
Serial.println("Incorrect password, sequence reset.");
// If key '6' is pressed, close the servo
if (key == '6' && servoOpen) {
myServo.write(0); // Close the servo
servoOpen = false;
lcd.clear();
lcd.print("Servo Closed");
Serial.println("Servo closed by pressing 6");
}
// Check if the servo should be closed due to inactivity
if (servoOpen && (millis() - lastKeyPressTime > INACTIVITY_TIMEOUT)) {
// Do nothing, inactivity timer has been replaced by manual '6' press
