RFID Lock system using Arduino | Arduino RFID door lock

Hey guys, welcome back to Techatronic. In this article, we are going to discuss a very interesting project with Arduino. Have you ever seen a smart lock in which you have to put the card on the reader to get access? Well, we will make our own smart lock, an RFID lock system that needs a unique card to perform a specific action. We are using an RC522 RFID reader/writer module and an Arduino UNO board for making this smart lock. You can view the card status on a 16×2 LCD that we used here. Do check out more interesting projects on Arduino and Raspberry Pi made by us.

Working of the Project

The RFID lock system works as when you will put the correct card to open the servo lock then “card is valid” this message will display and the green LED will turn on. The door will close automatically after a delay of three seconds, you can adjust this time in the code. For the invalid card the red LED will turn on with the message “card is invalid” and the buzzer starts beeping. The servo motor will rotate to open or close the gate. When you put an RFID card on the reader module then open the serial monitor to view the tag id of that card as shown below.

Add the tag id of the card that you want to use to open the lock in this section of the code.

Components Required

Arduino UNO
16×2 LCD and I2C module
Servo motor and buzzer
Green and red LED
Jumper wires and a breadboard
RC522 RFID module
220-ohm resistors and a 10K potentiometer
USB cable for uploading the code
Power supply

Arduino RFID Lock Circuit Diagram

With I2C module

If you are using the I2C module then find the address of the module first.

Arduino UNO	RFID – RC522 Module
10 Pin	SDA Pin
13 Pin	SCK Pin
11 Pin	MOSI Pin
12 Pin	MISO Pin
No Pin	IRQ Pin
GND	GND
9 Pin	RST Pin
3.3 V	3.3 V
Arduino UNO	Servo Motor
D3 Pin	OUT Pin ( Orange Colour )
( +5V )	VCC ( Red Colour )
GND	GND ( Black Colour )
Arduino UNO	I2C LCD Module
( +5V )	( +5V )
GND	GND
A4 Pin	SDA Pin
A5 Pin	SCL Pin
*16 2 LCD**	I2C LCD Module
16 Pin Connect	16 Pin Connect
Arduino UNO	Buzzer
D6 Pin	Positive
GND	Negative
Arduino	LED R	LED G	220 Ohm Resistor
D7 Pin	Anode Pin
D5 Pin		Anode Pin
GND			Terminal 1
	Cathode Pin	Cathode Pin	Terminal 2

You can take a reference from one of our articles on I2C with LCD.

Arduino GND pin -> RFID GND pin, I2C GND pin, Servo negative wire, buzzer negative leg, LEDs negative leg via 220-ohm resistor

Arduino 5 volts -> I2C VCC pin, Servo positive wire

RFID 3.3 volts -> Arduino 3.3 volts

RFID RST pin -> digital-9 pin

RFID MISO pin -> digital-12 pin

RFID MOSI pin -> digital-11 pin

RFID SCK pin -> digital-13 pin

RFID SDA pin -> digital-10 pin

Green LED positive leg -> digital-5 pin

Red LED positive leg -> digital-7 pin

Buzzer positive leg -> digital-6 pin

Without I2C module

Arduino UNO	RFID – RC522 Module
10 Pin	SDA Pin
13 Pin	SCK Pin
11 Pin	MOSI Pin
12 Pin	MISO Pin
No Pin	IRQ Pin
GND	GND
9 Pin	RST Pin
3.3 V	3.3 V
Arduino UNO	Servo Motor
D3 Pin	OUT Pin ( Orange Colour )
( +5V )	VCC ( Red Colour )
GND	GND ( Black Colour )
Arduino UNO	Buzzer
D6 Pin	Positive
GND	Negative
Arduino UNO	*162 LCD**	10K Potentiometer
GND	VSS, K
+5 V	VDD, A
GND	VSS (Ground)	Terminal 1
	VEE ( Contrast )	Terminal 2
+5 V	VDD ( +5V )	Terminal 3
A0 Pin	RS ( Register Select )
GND	RW ( Read\Write )
A1 Pin	E ( Enable )
A2 Pin	D4
A3 Pin	D5
A4 Pin	D6
A5 Pin	D7
Arduino	LED R	LED G	220 Ohm Resistor
D7 Pin	Anode Pin
D5 Pin		Anode Pin
GND			Terminal 1
	Cathode Pin	Cathode Pin	Terminal 2

All the connections are the same except the I2C module. Connect the LCD pins with the analog pins of the Arduino as shown in the diagram. You can take help from our article on the working of LCD with Arduino.

Arduino Rfid Lock Code

NOTE: Please upload the given code according to the circuit you have made. Install <SPI.h>, <MFRC522.h>, <LiquidCrystal_I2C.h>, <Wire.h> libraries to the IDE first and then compile the code. Check here to know how to install a zip library to the Arduino IDE.

With I2C module

 // TECHATRONIC.COM  
 // SPI Library  
 // https://github.com/PaulStoffregen/SPI  
 // MFRC522 Library  
 // https://github.com/miguelbalboa/rfid  
 #include <SPI.h>  
 #include <MFRC522.h>  
 #include <Servo.h>  
 #include <Wire.h>   
 #include <LiquidCrystal_I2C.h>  
 LiquidCrystal_I2C lcd(0x3F,16,2);  
 Servo s1;  
 #define SS_PIN 10  
 #define RST_PIN 9  
 #define LED_G 5  //define green LED pin  
 #define LED_R 7  //define red LED  
 #define BUZZER 6 //buzzer pin  
 MFRC522 mfrc522(SS_PIN, RST_PIN);  // Create MFRC522 instance.  
 //Servo myServo; //define servo name  
 void setup()   
 {  
  Serial.begin(9600);  // Initiate a serial communication  
  SPI.begin();     // Initiate SPI bus  
   lcd.init();             
  lcd.backlight();  
 ;  
  mfrc522.PCD_Init();  // Initiate MFRC522  
  s1.attach(3); //servo pin  
  // myServo.write(0); //servo start position  
  pinMode(LED_G, OUTPUT);  
  pinMode(LED_R, OUTPUT);  
  pinMode(BUZZER, OUTPUT);  
  noTone(BUZZER);  
  Serial.println("Put your card to the reader...");  
  Serial.println();  
  lcd.setCursor(0,0);  
  lcd.print(" Put your card   ");  
 }  
 void loop()   
 {  
  // Look for new cards  
  if ( ! mfrc522.PICC_IsNewCardPresent())   
  {  
   return;  
  }  
  // Select one of the cards  
  if ( ! mfrc522.PICC_ReadCardSerial())   
  {  
   return;  
  }  
  //Show UID on serial monitor  
  Serial.print("UID tag :");  
  String content= "";  
  byte letter;  
  for (byte i = 0; i < mfrc522.uid.size; i++)   
  {  
    Serial.print(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " ");  
    Serial.print(mfrc522.uid.uidByte[i], HEX);  
    content.concat(String(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " "));  
    content.concat(String(mfrc522.uid.uidByte[i], HEX));  
  }  
  Serial.println();  
  Serial.print("Message : ");  
  content.toUpperCase();  
  if (content.substring(1) == "5B 2F 4B 0C") //change here the UID of the card/cards that you want to give access  
  {  
   Serial.println("Authorized access");  
   Serial.println();  
     lcd.setCursor(0,0);  
     lcd.print(" CARD IS VALID      ");  
     lcd.setCursor(0,1);  
     lcd.print("Opening the Door   ");  
     digitalWrite(LED_G, HIGH); //Green LED ON  
     s1.write(0);  
     delay(3000);  
     s1.write(90);  
     lcd.setCursor(0,1);  
     lcd.print("closing the Door   ");  
     digitalWrite(LED_G, LOW);  //Green LED OFF  
     delay(2000);  
     lcd.setCursor(0,0);  
     lcd.print(" Put your card   ");  
     lcd.setCursor(0,1);  
     lcd.print("              ");  
  }  
  else   
  {  
   Serial.println("CARD IS INVALID");  
    lcd.setCursor(0,1);  
    lcd.print("CARD IS INVALID   ");  
    digitalWrite(LED_R, HIGH);   // Red LED ON  
    tone(BUZZER, 300);       // Buzzer ON  
    delay(2000);  
    digitalWrite(LED_R, LOW);  
    noTone(BUZZER);  
    lcd.setCursor(0,1);  
    lcd.print("              ");  
  }  
 }

Without I2C module

 // TECHATRONIC.COM  
 // SPI Library  
 // https://github.com/PaulStoffregen/SPI  
 // MFRC522 Library  
 // https://github.com/miguelbalboa/rfid  
 #include <SPI.h>  
 #include <MFRC522.h>  
 #include <Servo.h>  
 #include <Wire.h>   
 #include "LiquidCrystal.h"  
 LiquidCrystal lcd(A0, A1, A2, A3, A4, A5);  
 Servo s1;  
 #define SS_PIN 10  
 #define RST_PIN 9  
 #define LED_G 5  //define green LED pin  
 #define LED_R 7  //define red LED  
 #define BUZZER 6 //buzzer pin  
 MFRC522 mfrc522(SS_PIN, RST_PIN);  // Create MFRC522 instance.  
 //Servo myServo; //define servo name  
 void setup()   
 {  
  Serial.begin(9600);  // Initiate a serial communication  
  SPI.begin();     // Initiate SPI bus  
  lcd.begin(16,2);  
  mfrc522.PCD_Init();  // Initiate MFRC522  
  s1.attach(3); //servo pin  
  // myServo.write(0); //servo start position  
  pinMode(LED_G, OUTPUT);  
  pinMode(LED_R, OUTPUT);  
  pinMode(BUZZER, OUTPUT);  
  noTone(BUZZER);  
  Serial.println("Put your card to the reader...");  
  Serial.println();  
  lcd.setCursor(0,0);  
  lcd.print(" Put your card   ");  
 }  
 void loop()   
 {  
  // Look for new cards  
  if ( ! mfrc522.PICC_IsNewCardPresent())   
  {  
   return;  
  }  
  // Select one of the cards  
  if ( ! mfrc522.PICC_ReadCardSerial())   
  {  
   return;  
  }  
  //Show UID on serial monitor  
  Serial.print("UID tag :");  
  String content= "";  
  byte letter;  
  for (byte i = 0; i < mfrc522.uid.size; i++)   
  {  
    Serial.print(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " ");  
    Serial.print(mfrc522.uid.uidByte[i], HEX);  
    content.concat(String(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " "));  
    content.concat(String(mfrc522.uid.uidByte[i], HEX));  
  }  
  Serial.println();  
  Serial.print("Message : ");  
  content.toUpperCase();  
  if (content.substring(1) == "5B 2F 4B 0C") //change here the UID of the card/cards that you want to give access  
  {  
   Serial.println("Authorized access");  
   Serial.println();  
     lcd.setCursor(0,0);  
     lcd.print(" CARD IS VALID      ");  
     lcd.setCursor(0,1);  
     lcd.print("Opening the Door   ");  
     digitalWrite(LED_G, HIGH); //Green LED ON  
     s1.write(0);  
     delay(3000);  
     s1.write(90);  
     lcd.setCursor(0,1);  
     lcd.print("closing the Door   ");  
     digitalWrite(LED_G, LOW);  //Green LED OFF  
     delay(2000);  
     lcd.setCursor(0,0);  
     lcd.print(" Put your card   ");  
     lcd.setCursor(0,1);  
     lcd.print("              ");  
  }  
  else   
  {  
   Serial.println("CARD IS INVALID");  
    lcd.setCursor(0,1);  
    lcd.print("CARD IS INVALID   ");  
    digitalWrite(LED_R, HIGH);   // Red LED ON  
    tone(BUZZER, 300);       // Buzzer ON  
    delay(2000);  
    digitalWrite(LED_R, LOW);  
    noTone(BUZZER);  
    lcd.setCursor(0,1);  
    lcd.print("              ");  
  }  
 }

Please share your views and suggestions regarding this project. If you have any doubts then feel free to use the comments section below.

HAPPY LEARNING!

RFID Lock System With Servo Using Arduino

Working of the Project

Components Required

Arduino RFID Lock Circuit Diagram

With I2C module

Without I2C module

Arduino Rfid Lock Code

With I2C module

Without I2C module

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