RFID Door Lock System

• Arduino UNO R3 Development Board

• RC522 RFID Reader

• RFID Cards or Tags

• Solenoid Door Lock

• Single Channel Relay Module

• 16×2 LCD Display along with I2C Expansion Module

• Jumper Wires

• Power Supply Adaptor

In the next section, we will see the circuit diagram for the Arduino-based RFID Door Lock System.

 RFID Door Lock System using Arduino Circuit Diagram

The below RFID Door Lock System circuit diagram represents how an Arduino, RFID Module, Relay module, Solenoid Lock, and LCD display are connected to create a secure and automated door lock system.

This setup makes our Door to unlock only when an authorized RFID tag or RFID card gets scanned. Below you can find our actual hardware setup of the Arduino RFID Door Lock System developed by using Circuit Diagram and Pin Connection Details as a reference. We have built a lot of RFID based projects previously, if you are completely new RFID and would like to understand the basics of RFID and how it works with Arduino you can read our Arduino RFID tutorial before proceeding with this project.

As you can see the hardware connections are pretty easy and straightforward. We have the Arduino UNO board which acts as the main brain of this project. The RC522 RFID reader module is used to read the RFID cards and the 16×2 LCD is used to display the status information. The 12V solenoid lock is connected through a relay module to our Arduino UNO board. The set-up is powered buy a 12V lithium battery pack making the project portable and easy to install, you can also use 12V adapter with Arduino UNO if you do not have a battery.

To make the hardware connection easy to understadn we have given a table below which explains the connection between your Arduino board and the RFID, LCD and Relay modules.

Connection Between Arduino and RFID Reader

Connection Between Arduino and I2C LCD Display

Connection Between Arduino and Relay Module

Now that the hardware is ready lets move on to the programming section of our rfid door locking system. But before we do that its important to understadn that the Arduino code for this project is split into two sections, this is because each RFID card or Tag will have a unique ID number and it is important to know this unique ID of you RFID card to be able to grant access to it. So in the first section of code we will place your RFID card on a reader and read this unique ID and int he second section of code we will use this unique ID to build our rfid door locking system.