Arduino RFID Door Lock Access Control Project

We will learn what RFID is, how it works and how to make an Arduino based RFID door lock

Supplies

MFRC522 RFID module

Servo motor

LCD display

Arduino Board

Breadboard and jumper wires

Proximity sensor

Step 1: Work Process

First we have to set up a master tag, then the system goes into normal mode. If we scan an unknown tag, access will be denied, but if we scan the master, we will go into program mode from where we can add and authorize unknown tags. So now if we scan the tag again, access will be granted so we can open the door. After we close the door, it will automatically lock. If we want to remove a tag from the system, we just need to go into program mode again, scan the know tag, and it will be removed.

Step 2: Circuit Schematic

Step 3: Coding

Now let's take a look at the code. So first we need to include the libraries for the RFID module, display and servo motor, define some variables required for the following program and create an instance of the library.

This is the complete code of the project,

/*

* Arduino Door Lock Access Control Project

*

* by Dejan Nedelkovski, www.HowToMechatronics.com

*

* Library: MFRC522, https://github.com/miguelbalboa/rfid

*/

#include <SPI.h>

#include <MFRC522.h>

#include <LiquidCrystal.h>

#include <Servo.h>

#define RST_PIN 9

#define SS_PIN 10

byte readCard[4];

char* myTags[100] = {};

int tagsCount = 0;

String tagID = "";

boolean successRead = false;

boolean correctTag = false;

int proximitySensor;

boolean doorOpened = false;

// Create instances

MFRC522 mfrc522(SS_PIN, RST_PIN);

LiquidCrystal lcd(2, 3, 4, 5, 6, 7); //Parameters: (rs, enable, d4, d5, d6, d7)

Servo myServo; // Servo motor

void setup() {

// Initiating

SPI.begin(); // SPI bus

mfrc522.PCD_Init(); // MFRC522

lcd.begin(16, 2); // LCD screen

myServo.attach(8); // Servo motor

myServo.write(10); // Initial lock position of the servo motor

// Prints the initial message

lcd.print("-No Master Tag!-");

lcd.setCursor(0, 1);

lcd.print(" SCAN NOW");

// Waits until a master card is scanned

while (!successRead) {

successRead = getID();

if ( successRead == true) {

myTags[tagsCount] = strdup(tagID.c_str()); // Sets the master tag into position 0 in the array

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("Master Tag Set!");

tagsCount++;

}

}

successRead = false;

printNormalModeMessage();

}

void loop() {

int proximitySensor = analogRead(A0);

// If door is closed...

if (proximitySensor > 200) {

if ( ! mfrc522.PICC_IsNewCardPresent()) { //If a new PICC placed to RFID reader continue

return;

}

if ( ! mfrc522.PICC_ReadCardSerial()) { //Since a PICC placed get Serial and continue

return;

}

tagID = "";

// The MIFARE PICCs that we use have 4 byte UID

for ( uint8_t I = 0; I < 4; i++) { //

readCard[i] = mfrc522.uid.uidByte[i];

tagID.concat(String(mfrc522.uid.uidByte[i], HEX)); // Adds the 4 bytes in a single String variable

}

tagID.toUpperCase();

mfrc522.PICC_HaltA(); // Stop reading

correctTag = false;

// Checks whether the scanned tag is the master tag

if (tagID == myTags[0]) {

lcd.clear();

lcd.print("Program mode:");

lcd.setCursor(0, 1);

lcd.print("Add/Remove Tag");

while (!successRead) {

successRead = getID();

if ( successRead == true) {

for (int I = 0; I < 100; i++) {

if (tagID == myTags[i]) {

myTags[i] = "";

lcd.clear();

lcd.setCursor(0, 0);

lcd.print(" Tag Removed!");

printNormalModeMessage();

return;

}

}

myTags[tagsCount] = strdup(tagID.c_str());

lcd.clear();

lcd.setCursor(0, 0);

lcd.print(" Tag Added!");

printNormalModeMessage();

tagsCount++;

return;

}

}

}

successRead = false;

// Checks whether the scanned tag is authorized

for (int I = 0; I < 100; i++) {

if (tagID == myTags[i]) {

lcd.clear();

lcd.setCursor(0, 0);

lcd.print(" Access Granted!");

myServo.write(170); // Unlocks the door

printNormalModeMessage();

correctTag = true;

}

}

if (correctTag == false) {

lcd.clear();

lcd.setCursor(0, 0);

lcd.print(" Access Denied!");

printNormalModeMessage();

}

}

// If door is open...

else {

lcd.clear();

lcd.setCursor(0, 0);

lcd.print(" Door Opened!");

while (!doorOpened) {

proximitySensor = analogRead(A0);

if (proximitySensor > 200) {

doorOpened = true;

}

}

doorOpened = false;

delay(500);

myServo.write(10); // Locks the door

printNormalModeMessage();

}

}

uint8_t getID() {

// Getting ready for Reading PICCs

if ( ! mfrc522.PICC_IsNewCardPresent()) { //If a new PICC placed to RFID reader continue

return 0;

}

if ( ! mfrc522.PICC_ReadCardSerial()) { //Since a PICC placed get Serial and continue

return 0;

}

tagID = "";

for ( uint8_t I = 0; I < 4; i++) { // The MIFARE PICCs that we use have 4 byte UID

readCard[i] = mfrc522.uid.uidByte[i];

tagID.concat(String(mfrc522.uid.uidByte[i], HEX)); // Adds the 4 bytes in a single String variable

}

tagID.toUpperCase();

mfrc522.PICC_HaltA(); // Stop reading

return 1;

}

void printNormalModeMessage() {

delay(1500);

lcd.clear();

lcd.print("-Access Control-");

lcd.setCursor(0, 1);

lcd.print(" Scan Your Tag!");

}