Suggested Reading; Serial Communication; Hardware Overview - Sparkfun Electronics GT-521F Series Hook-Up Manual

Suggested Reading

Depending on how you are connecting to the fingerprint scanner, you may need to know the following concepts before working with one of these boards:
How to Solder: Through-Hole Soldering
This tutorial covers everything you need to know about through-hole soldering.
Installing an Arduino Library
How do I install a custom Arduino library? It's easy!
Serial Terminal Basics
This tutorial will show you how to communicate with your serial devices using a
variety of terminal emulator applications.

Hardware Overview

Features
The GT-521F32 and GT-521F52 have a lot in common with the previous models. They have the same protocol commands and packet structure. Code that was implemented
for previous models should be functionally the same. The fingerprint scanner has the ability to:
Enroll a Fingerprint
Identify a Fingerprint
Capable of 360° Recognition
However, there are a few differences in the boards. These include:
Different Board Layout
4x Mounting Holes
2x JST SH Connectors
Touch Interface
One significant difference to keep in mind when integrating the fingerprint scanner in a project is the number of fingerprints that the device can hold. The GT-521F32 costs less
but it can hold only 200 fingerprints. The GT-521F52 is slightly more expensive but it can hold 3000 fingerprints.
Technical Specs
CPU
Sensor
Window

Serial Communication

Asynchronous serial communication concepts: packets, signal levels, baud rates,
UARTs and more!
Logic Levels
Learn the difference between 3.3V and 5V devices and logic levels.
GT-521F32 / GT-521F52
ARM Cortex M3 Cortex
optical
16.9mm x 12.9mm