Published May 22, 2023 © GPL3+

Open a Door Lock with a Ring

How to Open a Door Lock with a Ring

BeginnerFull instructions provided2 hours348

Things used in this project

Hardware components

Arduino UNO

RFID Reader

Motor Driver L298n

Jumper wires (generic)

2s Battery Holder

3.7v Batteries

Software apps and online services

Arduino IDE

Story

In this tutorial, we will show you how to use an Arduino and RF-ID reader to create a smart door lock that can be opened with a ring. We'll guide you through the process step by step, from assembling the hardware to programming the Arduino. I get RF-ID tag from RF-ID card and paste this tag on the ring and then ring can be used for door opener. This is a great project for anyone interested in home automation or DIY electronics.

Code

#define lockPin A0
#define unlockPin A1

#include <SPI.h>
#include <MFRC522.h>

#define SS_PIN 10
#define RST_PIN 9
MFRC522 mfrc522(SS_PIN, RST_PIN);   // Create MFRC522 instance.
int x = 1;
void setup()
{
  pinMode(lockPin, OUTPUT);
  pinMode(unlockPin, OUTPUT);
  Serial.begin(9600);   // Initiate a serial communication
  SPI.begin();      // Initiate  SPI bus
  mfrc522.PCD_Init();   // Initiate MFRC522
  Serial.println("Approximate your card to the reader...");
  Serial.println();

}
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) == "C1 BA 3E 19") || (content.substring(1) == "63 78 52 2E")) //change here the UID of the card/cards that you want to give access
  {
    Serial.println("Authorized access");
    Serial.println();
    if (x == 1)
    {
      x=0;
      Serial.println("if statement execute");
      digitalWrite(lockPin, HIGH);
      delay(500);
      digitalWrite(lockPin, LOW);
      
      
    }
    else if (x == 0)
    {
      x=1;
      Serial.println("else if statement execute");
      digitalWrite(unlockPin, HIGH);
      delay(500);
      digitalWrite(unlockPin, LOW);
      
    }
  }

  else   {
    Serial.println(" Access denied");
    delay(3000);
  }
}