RFID example.ino

//Viral Science www.viralsciencecreativity.com www.youtube.com/c/viralscience
//RFID Door Lock System

#include <Wire.h>
#include <SPI.h>
#include <MFRC522.h>
#include <LiquidCrystal.h>
 
#define SS_PIN 53
#define RST_PIN 49
#define LED_G 4 //define green LED pin
#define LED_R 5 //define red LED
#define BUZZER 13 //buzzer pin
#define lock 48

LiquidCrystal lcd(2, 3, 14, 15, 16, 17);
MFRC522 mfrc522(SS_PIN, RST_PIN);   // Create MFRC522 instance.
int Btn = 6;
 
void setup() {
	Serial.begin(9600);   // Initiate a serial communication
	SPI.begin();      // Initiate  SPI bus
	mfrc522.PCD_Init();   // Initiate MFRC522
	pinMode(LED_G, OUTPUT);
	pinMode(LED_R, OUTPUT);
	pinMode(BUZZER, OUTPUT);
	noTone(BUZZER);
	pinMode(Btn,INPUT);
	pinMode(lock,OUTPUT);
	Serial.println("Place your card on reader...");
	Serial.println();
	lcd.begin(16,2);
	lcd.clear();
	lcd.setCursor(0,0); // column, row
	lcd.print(" Scan Your RFID "); 
	lcd.setCursor(0,1); // column, row
	lcd.print("   Door Locked   ");
}
void loop() {
	// if(digitalRead(Btn) == HIGH) {
	// 	Serial.println("Access Granted");
	// 	Serial.println();
	// 	delay(500);
	// 	digitalWrite(LED_G, HIGH);
	// 	lcd.setCursor(0,1); // column, row
	// 	lcd.print(" Door Un-Locked ");
	// 	tone(BUZZER, 2000);
	// 	delay(100);
	// 	noTone(BUZZER);
	// 	delay(50);
	// 	tone(BUZZER, 2000);
	// 	delay(100);
	// 	noTone(BUZZER);
	// 	digitalWrite(lock,HIGH);
	// 	delay(3000);
	// 	digitalWrite(lock,LOW);
	// 	delay(100);
	// 	digitalWrite(LED_G, LOW);
	// 	lcd.setCursor(0,1); // column, row
	// 	lcd.print("   Door Locked   ");
	// 	tone(BUZZER, 2000);
	// 	delay(100);
	// 	noTone(BUZZER);
	// 	delay(50);
	// }

	// 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) == "EB 4A 92 22") { //change here the UID of card/cards or tag/tags that you want to give access
		Serial.println("Access Granted");
		Serial.println();
		delay(500);
		// digitalWrite(LED_G, HIGH);
		lcd.setCursor(0,1); // column, row
		lcd.print(" Door Un-Locked ");
		// tone(BUZZER, 2000, 100);
		delay(50);
		// tone(BUZZER, 2000, 100);
		digitalWrite(lock,HIGH);
		delay(3000);
		digitalWrite(lock,LOW);
		delay(100);
		// digitalWrite(LED_G, LOW);
		lcd.setCursor(0,1); // column, row
		lcd.print("   Door Locked   ");
		// tone(BUZZER, 2000, 100);
		delay(50);
	} else {
		lcd.setCursor(0,1); // column, row
		lcd.print("Invalid RFID Tag");
		Serial.println(" Access denied");
		for (int i = 0; i < 3; i++)
		{
			// digitalWrite(LED_R, HIGH);
			// tone(BUZZER, 1500, 500);
			// digitalWrite(LED_R, LOW);
			delay(100);
		}
		lcd.setCursor(0,1); // column, row
		lcd.print("   Door Locked   ");
	}
}