How Optical Fingerprint Scanners Work with Arduino: A Beginner's Guide

Optical fingerprint scanners are an essential component in various applications, including security systems and biometric identification. In this tutorial, we will explore the basics of how optical fingerprint scanners work and how you can interface the R307 fingerprint scanner module with an Arduino board.

There are several methods to digitize fingerprints, ranging from forensic techniques to ultrasound scanning. One popular method is using a serial link between a PC and a fingerprint scanner module, which has some limitations due to the speed of the software serial port used for the FPS or synchronisation issues between the two serial ports.

The R307 fingerprint scanner module can be connected to an Arduino Uno board using a USB adapter. The module comes with a demo application that runs on Windows, requiring a USB-to-TTL adapter to connect it to the PC. Fortunately, there are libraries available to help you use this sensor with Arduino, such as the adafruit fingerprint library.

To start, place a finger on the scanner to see if it has been enrolled and what the ID is. To identify that a user's fingerprint has been enrolled and find the ID of that user's fingerprint, click the Identify(1:N) button. The user will be prompted to place their finger on the fingerprint scanner.

To enroll a new user, first select an unused ID in the ID box. The number of fingerprints stored will be displayed in the Result box at the bottom of the window.

The Arduino Uno board is configured to relay information between the USB port and the fingerprint scanner module using voltage divider resistors. Some alternative resistor combinations for the resistor divider can be found below the circuit diagram.

In this article, we will learn how an Optical Fingerprint Scanner works and how we can interface the R307 fingerprint scanner module to an Arduino board. By understanding the basics of optical fingerprint scanners and how they work with Arduino, you can create your own biometric identification system or integrate it into your existing project.

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