Sensors - Tranducers Circuits

Biometric Attendance System Circuit

Biometrics is a new type of identifying technology. The term “biometric” Attendence refers to the automatic identification of a person using biological characteristics such as fingerprints, iris scans, and facial recognition. A finger print-based attendance system is proposed in this article. Attendance at educational institutions and in the workplace will necessitate more paperwork and time. To combat this, a finger print-based automatic attendance system was developed. Biometric Attendance System is another name for it. We’ve already shown how to use an AVR Microcontroller to create an RFID-based attendance system. We’ll show you how to make a biometric attendance system circuit with an AVR microcontroller in this article.


  • Biometric Attendance System Circuit Principle:
  • Biometric Attendance System Circuit Diagram:
    • Biometric Attendance System Circuit Design:
    • Working of Fingerprint Based Attendance System Circuit:
    • Biometric Attendance System Circuit Applications:
      • Limitations of the Circuit:

Biometric Attendance System Circuit Principle:

This circuit’s main goal is to take attendance and display it when it is asked.

Fingerprint recognition is based on the fact that no two people in the world have the same fingerprint. This is due to the unique genetic coding of each individual’s DNA. The ridges and valleys on a finger print are used by the finger print module to distinguish between two fingers. When a finger print is given, several algorithms are used to save the spots where the direction of ridges and valleys changes. A DSP processor is incorporated inside the finger print module to implement and analyse the algorithm.

The finger print module is the circuit’s beating heart. When a finger print is matched, this transmits orders to the controller. The microcontroller receives these commands from the finger print module and stores the attendance in the internal EEPROM. The keypad is used to convey commands to the controller, such as enrolling a new user, saving attendance, or exiting. The messages linked to the commands received are displayed on the LCD display.

Biometric Attendance System Circuit Diagram:

Biometric Attendance System Circuit

Circuit Diagram of Biometric Attendance System

Circuit Components:

  • AVR microcontroller development board.
  • Fingerprint module R305.
  • Keypad (4*3).
  • Atmega8 microcontroller
  • RS232 Serial cable.
  • DC Battery or Adaptor (12V, 1Amp).
  • 16*2 Alpha Numeric LCD.
  • Single pi connecting wires.

Biometric Attendance System Circuit Design:

We utilised an ATmega8 microprocessor from the AVR family in this project. It’s a microcontroller with an 8-bit resolution and 23 programmable input and output pins. It has an 8-KB flash memory, 512-byte EEPROM, and 1-KB SRAM.

The R305 series finger print module was used in this biometric module. It is compatible with the USART communication protocol. The microcontroller is communicated with using the USART protocol. The Universal Synchronous and Asynchronous Receiver and Transmitter (USART) is a universal synchronous and asynchronous receiver and transmitter. There are four pins on this module: 1) Transmit, 2) Receive, 3) Vin, and 4) GND. The microcontroller’s transmit pin is connected to the receive pin. The microcontroller’s transmit pin should be connected to the receiver pin. Vin is a great guy.GND is connected to ground and a voltage of 5V is applied. Serial communication can be used to send and receive data.

Two processes are involved in the processing of finger prints. Finger enrollment and finger matching are the first two steps. To enrol, the user must first present his finger print to the module twice. The module compares the two images and creates and saves a template image. The input finger print is matched 1:1 with the template picture generated in the second step of finger matching, and an acknowledgement is generated. For 1: N matching input, the photos in the library are matched. It returns the matching image and generates a page id for the matched image.

This project uses a 4*3 keypad, which has four rows and three columns. The microcontroller’s PORT D pins are connected to the keypad’s columns. The three columns of the keypad are connected via PD5 to PD7 pins. The microcontroller’s PORT C is connected to the rows. The rows of the keypad are attached to the PC0 through PC3 pins. Press 1 on the keypad to take attendance, 2 on the keypad to enrol, and 3 on the keypad to clear all the data.

The texts are displayed on a liquid crystal display. This is connected to the microcontroller’s PORTB. The microcontroller is coupled to a 4-bit LCD. The microcontroller’s PB0-PB3 pins are connected to the D4-D7 pins. The RS pin is connected to the PB4, the RW pin to the PB5, and the Enable pin to the PB6 pin.

Working of Fingerprint Based Attendance System Circuit:

  1. Power the AVR development board.
  2. Burn the code into the microcontroller using serial cable.
  3. While burning the code make sure that slide switch is in programming mode.
  4. After the code has been burned, turn off the power and detach the serial cable.
  5. Now connect the circuit as shown in the diagram.
  6. LCD will display “Biometric Attendance System”.

7.After a while, the message “1.Attendance, 2.Save, 3.Clear” will appear.
8..Now, on the keypad, hit 1. If you place your finger on the module, it will take your attendance. It will indicate the same if your finger is not matched.
9..Press 2 on the keyboard if you want to preserve your roll number. It will prompt you to enter the roll number and place your finger on the screen. Your information is successfully saved, and a message is displayed.
10.To re-enroll, hit 1 on the keypad, then 2 to quit.
11.To clear the data, press 3 on the keypad and then input the password.

Biometric Attendance System Circuit Applications:

  • This is something that can be used in educational settings.
  • In industries, a biometric attendance system can be employed.
  • Biometrics can be used to authenticate ATM users.
  • Access control can make use of fingerprint authentication.

Limitations of the Circuit:

  • By placing a phoney finger print, there is a potential of misusing the device.
  • Modules are delicate and should be handled with care.

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