This document describes an IoT password door lock mini-project using an Arduino Uno. The system uses a keypad, LCD display, and micro servo motor to allow access through a door only when the correct password is entered. It is designed to provide secure access to homes, offices, or other places through a simple circuit with low power needs. The system architecture and code implementation are presented, along with advantages like programmable passwords and applications for security and access control.

1. PASSWORD DOOR
LOCK SYSTEM
IOT MINI-PROJECT

2. CONTENTS
● Introduction
● Motivation
● Objectives
● Requirements
● System Architecture
● Circuit Diagram
● Working
● Advantages and Applications
● Code and Implementation
● Conclusion
● Future scope
● References

3. INTRODUCTION
● This password-based door lock system allows access to
only authorized persons .
● It can be mounted to any of the existing doors .
● Less complicated components & embedded software are
used in this project.
● System is based on Arduino Uno along with a keypad , an
LCD and a Micro Servo.

4. MOTIVATION
● Today’s main concern is SECURITY.
● Conventional locks are not much safe.
● Rate of crime and intruders is increasing day by day.
● Access should be restricted to limited people.

5. OBJECTIVES
● To ensure better safety at residential places
● To give access of highly secured places in an organization
with only authorities
● To provide users more secure yet cost-efficient way of
door locking

6. REQUIREMENTS
Hardware:
● Arduino Uno
● LCD display
● Keypad
● Micro Servo Motor
● Resistors
● Connecting wires
● Battery
Software:
● Arduino Software (IDE)

7. ARDUINO UNO LCD DISPLAY
KEYPAD

8. MICRO SERVO RESISTORS
CONNECTING WIRES

9. SYSTEM ARCHITECTURE

10. FLOW CHART

11. CIRCUIT DIAGRAM

12. WORKING
● Arduino compares the original set password and the passkey
which we enter.
● The operation code is dumped into the Arduino board using the
dumping cable.
● LCD displays “Enter Password”.
● We enter passkey using keypad and passkey is displayed on
LCD.
● For correct passkey, LCD displays “Door is Open” and for wrong
“Access Denied” so door remain locked.

13. ADVANTAGES
● Simple programmable code lock circuit.
● Major components are only LCD, Keypad, Arduino,Micro servo.
● User can set his password for ensured protection instantly.
● Power required to operate this circuit is very less.

14. APPLICATIONS
● Used in doors of houses.
● Used for vehicles.
● Used for jewellery or money boxes.
● Used in secured offices and wherever security is needed.

15. CODE
#include <Keypad.h>
#include <LiquidCrystal.h>
#include <Servo.h>
#define Password_Length 5
Servo myservo;
LiquidCrystal lcd(A0, A1, A2, A3, A4, A5);
int pos = 0;
char Data[Password_Length];
char Master[Password_Length] =
"1234";
byte data_count = 0, master_count = 0;
bool Pass_is_good;
bool door = false;
char customKey;
/*---preparing keypad---*/
const byte ROWS = 4;
const byte COLS = 4;
char keys[ROWS][COLS] = {
{'1', '2', '3', 'A'},
{'4', '5', '6', 'B'},
{'7', '8', '9', 'C'},
{'*', '0', '#', 'D'}};
byte rowPins[ROWS] = {0, 1, 2, 3};
byte colPins[COLS] = {4, 5, 6, 7};
Keypad customKeypad( makeKeymap(keys), rowPins,
colPins, ROWS, COLS);
/*--- Main Action ---*/
void setup()
{
myservo.attach(9, 2000, 2400);
ServoClose();
lcd.begin(16, 2);
lcd.print("Protected Door");
loading("Loading");
lcd.clear();
}

16. CODE
void loop()
{
if (door == true)
{
customKey = customKeypad.getKey();
if (customKey == '#')
{
lcd.clear();
ServoClose();
lcd.print("Door is closed");
delay(3000);
door = false;
}
}
else
Open();
}
void loading (char msg[]) {
lcd.setCursor(0, 1);
lcd.print(msg);
for (int i = 0; i < 9; i++) {
delay(1000);
lcd.print(".");
}
}
void clearData()
{
while (data_count != 0)
{
Data[data_count--] = 0;
}
return;
}

17. CODE
void ServoClose()
{
for (pos = 90; pos >= 0; pos -= 10) {
myservo.write(pos);
}
}
void ServoOpen()
{
for (pos = 0; pos <= 90; pos += 10) {
myservo.write(pos);
}
}
void Open()
{
lcd.setCursor(0, 0);
lcd.print("Enter Password");
customKey = customKeypad.getKey();
if (customKey)
{
Data[data_count] = customKey;
lcd.setCursor(data_count, 1);
lcd.print(Data[data_count]);
data_count++;
}
if (data_count == Password_Length - 1)
{
if (!strcmp(Data, Master))
{
lcd.clear(); ServoOpen(); lcd.print(" Door is Open
"); door = true; delay(5000);
loading("Waiting"); lcd.clear(); lcd.print(" Time is
up! "); delay(1000); ServoClose(); door = false;
}
else{
lcd.clear();
lcd.print(" Wrong Password ");
door = false;
}delay(1000);lcd.clear(); clearData();}
}

18. IMPLEMENTATION
Link to Tinkercad : https://www.tinkercad.com/things/idKgClcD9yw-mighty-bombul-
jaban/editel?sharecode=wXB5NROP9SFsuUKz6U3VDD9_fe83ra-zZdH3oDqZXC8

19. CONCLUSION
● This digital code lock is very marketable because it is easy
to use.
● Comparatively inexpensive due to low power
consumption and highly reliable.
● This is most prevalent form of digital lock as it uses
numerical code for authentication.
● The code lock is therefore particularly useful in door locks
and equipment locks.

20. FUTURE SCOPE
● This project can be further extended by adding GSM
module, so that owner will receive the message to his
mobile, whenever the lock is being authenticated.
● This helps the locking system to be more secure.
● Also, we can keep a count for wrong entries of passkey,
such that the lock will be permanently locked if the count
reaches and it can’t be opened until the owner resets it.

21. REFERENCES
● https://circuitdigest.com/microcontroller-projects/digital-keypad-security-door-lock-using-
arduino
● https://arduinogetstarted.com/tutorials/arduino-door-lock-system-using-password
● https://www.youtube.com/watch?v=PATSL8ck8Ns
● https://how2electronics.com/password-based-security-system-arduino-keypad/
● https://www.irjet.net/archives/V6/i2/IRJET-V6I2225.pdf
● https://youtu.be/58jFAammYcw

22. THANK YOU