ESP32 Fingerprint Sensor Based Door Lock Security System

In this project, we will interface R305 Fingerprint Sensor with ESP32 Module to design a Smart Door Lock Security System.

Overview

Security is a major concern in our day to day life, and digital locks have become an important part of these security systems. Fingerprint sensor-based is one of the safest door locking system as it has the ability to identify and distinguish every person individually without making any error. The fingerprint-based security system can be used in many places like Industries, Offices, and Colleges or even at our home.

This project is a fine combination of “Biometrics technology” and “Embedded system technology”. We have seen a Password-based security system and RFID based security system, which is insecure and anyone can have access. The main feature or specialty of the fingerprint is that it is unique. It gives a high level of security than other security systems.

So in this project, we will learn how to make ESP32 Fingerprint Sensor Based Door Lock Security System. We will simply interface the R305 Fingerprint Sensor Module with ESP32 Development Board. We will use a Solenoid valve to lock/unlock the door. The 0.96″ SSD1306 OLED Display will display the status of matched/unmatched finger and door locking and unlocking status. The PCB board Gerber file and Source Code/Program written in Arduino IDE is shared below.

Bill of Materials

Following are the components required for this Security System Project. All the components can be easily purchased from Amazon. The component purchase link is given below.

Note: Ignore 4×4 Keypad in the above image. We don’t need it in this project.

R305 Fingerprint Sensor Module

The R305 Fingerprint Sensor has a high powered DSP chip that does the image rendering, calculation, feature-finding, and searching. Connect to any microcontroller or system with TTL serial, and send packets of data to take photos, detect prints, hash, and search. You can also enroll new fingers directly- up to 162 fingerprints can be stored in the onboard FLASH memory. There’s a red LED in the lens that lights up during a photo so you know its working.

Fingerprint processing includes two parts: fingerprint enrollment and fingerprint matching (the matching can be 1:1 or 1: N). When enrolling, a user needs to enter the finger two times. The system will process the two -time finger images, generate a template of the finger based on processing results, and store the template. When matching, the user enters the finger through an optical sensor, and the system will generate a template of the finger and compare it with templates of the finger library. For 1:1 matching, the system will compare the live finger with a specific template designated in the Module; for 1: N matching, or searching, the system will search the whole finger library for the matching finger. In both circumstances, the system will return the matching result, success or failure.

0.96″ OLED Display

This is a 0.96 inch blue OLED display module. The display module can be interfaced with any microcontroller using SPI/IIC protocols. It is having a resolution of 128×64. The package includes display board, display,4 pin male header pre-soldered to board.

OLED (Organic Light-Emitting Diode) is a self-light-emitting technology composed of a thin, multi-layered organic film placed between an anode and cathode. In contrast to LCD technology, OLED does not require a backlight. OLED possesses high application potential for virtually all types of displays and is regarded as the ultimate technology for the next generation of flat-panel displays.

Solenoid Lock

12V Solenoid lock has a slug with a slanted cut and a good mounting bracket. It’s basically an electronic lock, designed for a basic cabinet, safe or door. When 9-12VDC is applied, the slug pulls in so it doesn’t stick out and the door can be opened. It does not use any power in this state. It is very easy to install for automatic door lock systems like electric door lock with the mounting board. This solenoid, in particular, is nice and strong.

Circuit: ESP32 Fingerprint Sensor Door Lock Security System

Here is the circuit diagram/Schematic for ESP32 & R305 Fingerprint Sensor Based Biometric Door Lock Security System. ESP32 is heart of the circuit whcih controls all other components including Fingerprint Sensor, Solenoid Lock, OLED Display, Buzzer etc. The Schematic has been designed in EasyEDA.

It’s very difficult to assemble such many components on the breadboard. So we made a PCB and soldered the component there to make it easy to assemble. The final assembled circuit is given below.

PCB Designing & Gerber File

The PCB for ESP32 Fingerprint Sensor Based Door Lock Security System has been designed in EasyEDA online PCB making tool. Below is the front view and Back View of the PCB.

The Gerber File for the PCB is given below. You can simply download the Gerber File and order the PCB from ALLPCB at 1$ only.

PCB Ordering, Soldering & Mounting

You can use this Gerber file to order high quality PCB for this project. To do that visit the ALLPCB official website by clicking here: https://www.allpcb.com/.

You can now upload the Gerber File by choosing the Quote Now option. From these options, you can choose the Material Type, Dimensions, Quantity, Thickness, Solder Mask Color and other required parameters.

After filling all details, select your country and shipping method. Finally you can place the order.

So after a week I got the PCB from ALLPCB. The PCB quality is good and excellent.

After that you can solder all the necessary components as per circuit diagram and make the final product ready.

Source Code: Enrolling the Fingerprint

Before making this Door Lock Security System workable, you need to enroll the fingerprint. The only an enrolled finger can be used to open the door. The unregistered user won’t be able to get any access. The code for enrolling the fingerprint is given below. Copy this code and upload it to ESP32 Board.

But before that add the following libraries:
1. Fingerprint Sensor Library: Download
2. Adafruit GFX Library: Download
3. SSD1306 OLED Library: Download

Once the code is uploaded, you can open the serial monitor and set the baud rate to 57600. Then you can enroll the fingerprint as suggested in Serial Monitor Screen.

When enrolling, a user needs to enter the finger two times. The system will process the two -time finger images, generate a template of the finger based on processing results and store the template. When matching, the user enters the finger through an optical sensor and the system will generate a template of the finger and compare it with templates of the finger library.

Source Code: ESP32 Fingerprint Sensor Door Lock Security System

Once the enrolling is done, you can upload another code to the ESP32 board. The code is capable of locking and unlocking the door based on matched and unmatched cases. The code is given below.

System Operations & Results

Once the code is uploaded the OLED will display the fingerprint logo and Fingerprint Sensor will start blinking giving the indication to place the finger.

If an unregistered finger is placed on a sensor the OLED will display “Invalid Finger Try again”. At this moment. the door won’t open as Relay doesn’t turn on the Solenoid Lock.

If a registered finger is placed on a sensor the OLED will display “Door Unlocked, Welcome”. At this moment. the door will open as Relay turn on the Solenoid Lock.

Video Tutorial & Demo