The U20-ASF-BT2 is an advanced, stand-alone fingerprint recognition system that captures and stores fingerprint data and identifies or verifies registered users. It is the wireless member of SecuGen’s Unity OEM Modules: all-in-one, stand-alone fingerprint systems designed to function entirely without an external PC.


With its ultra-compact and rugged design, the U20-ASF-BT2 can be integrated into access control units, door locks, ATMs, handheld devices, laptops, point of sale equipment, industrial equipment and many other kinds of products. It can communicate with external devices via Bluetooth and is interoperable with data input from SecuGen USB fingerprint readers for a wide variety of implementations.


The U20-ASF-BT2 consists of the SecuGen U20-A, an FBI-Certified FAP 20 Fingerprint Sensor, integrated with a programmable Single-Board Computer (SBC) that includes on-board CPU, SDRAM, flash memory, and a Bluetooth module.

U20-ASF (front, side, rear views)

Features of Fingerprint Sensor


  • Rugged, high image quality fingerprint sensor that is both FBI Certified (PIV, FIPS 201, Mobile ID FAP 20 Compliant) and STQC Certified. Meets FBI Image Quality standardsThe fingerprint sensor was certified by the FBI as tested and in compliance with the FBI’s Next Generation Identification (NGI) Image Quality Specifications (IQS). The review of the test data was conducted by the FBI / Criminal Justice Information Services Division / Global Operations Section, as part of the Biometric Center of Excellence.
  • Built upon patented technologies that allow rapid capture of high-contrast, low-distortion fingerprint images
  • Smart Capture ensures high quality imaging even from traditionally difficult fingerprints, such as dry or moist fingers, as well as under very bright conditions, such as outdoors in sunlight
  • Auto-On for automatic detection of a finger when placed on the sensor

Bluetooth Features


  • Class 2 Bluetooth transceiver
  • Dual-mode Bluetooth / Low Energy (BLE) radio
  • Supports Serial Port Profile (SPP) for Bluetooth Classic
  • Provides emulation SPP for BLE (iOS interface support)
  • Small chip antenna

Features of Built-in Processor Board (SBC)


  • Fingerprint Management System (FMS) software that works right out of the box
  • Open Linux OS that lets you develop custom applications running on the device
  • Large fingerprint template storage capacity and support for SG400, ISO/ICE 19794-2, and single view ANSI INCITS 378-2004 templates
  • NIST MINEX Certified and FIPS 201 Compliant embedded fingerprint algorithms for template generation and matching
  • High-speed fingerprint matching in verification mode (1:1) or identification mode (1:N, using built-in SecuSearch Engine)
  • Interoperable with data input from SecuGen USB fingerprint readers to support a wide variety of implementations
  • Responds to serial commands that use the same protocol supported by SecuGen’s SDA04P-series OEM modules

Technical Specifications


  • Model
  • Certification
  • CPU
  • Operating System
  • Template Capacity
  • Host Communication
  • External Interface
  • Sensor (Type)
  • Image Resolution
  • Platen Size
  • Sensing Area
  • Image Grayscale
  • Light Source
  • Supported Fingerprint Templates
  • Other Features
  • Supply Voltage
  • Current Consumption
  • Dimensions
  • Weight
  • Operating Temperature
  • Water Resistance
  • Bluetooth Specifications


  • U20-ASF-BT2
  • 1 GHz MIPS
  • Linux Kernel 3.10.14
  • 1,400 (1:1 and 1:N)
  • Serial (CMOS 3.3V)
  • GPIO, Wiegand
  • U20-A (contact)
  • 500 PPI
  • 18.2 mm x 23.1 mm
  • 15.24 mm x 20.32 mm
  • 256 levels (8-bit)
  • Green LED
  • SecuGen Proprietary, ANSI INCITS 378-2004, and ISO/IEC 19794-2 formats
  • Auto-On™, Smart Capture™, Device Recognition™, 360 Degree Fingerprint Rotation
  • 3.3V or 5V
  • 200 mA @ 5V (max)
  • 34.0 mm x 49.0 mm x 22.9 mm
  • 25 g
  • -20° ~ 65°C
  • Available (applied to optic module)
  • Bluetooth V4.2 (HS) with Integrated Class 1.5 PA and Low Engery (BLE) support
    BT host digital interface: UART (up to 4 Mbps)
    Coexisting IEEE wireless technology on integrated die solution

Advantages of U20-ASF-BT2


Non-optical fingerprint sensors based on capacitive or semiconductor technology are frail in comparison with the U20-ASF-BT2, which can withstand extreme environmental conditions, heavy use, as well as external shock, scratches and impact. This makes it an ideal solution for a diverse range of applications, especially those used in outdoor, rugged, and high-traffic environments. Its compact size makes it smaller than most other optical fingerprint devices so that it can be more easily integrated into a wider range of applications.

Typical Applications


The U20-ASF-BT2 was designed to satisfy today’s growing need for security applications that require standalone, embedded fingerprint systems such as:


  • Physical access control systems
  • Door-lock systems (indoor/outdoor)
  • Time & attendance systems
  • Cabinet safes and vaults (gun safes, safe deposit boxes)
  • Vehicle access control
  • Automatic teller machines (ATM)
  • Point-of-sale machines (POS), kiosks
  • Verification of credit cards/smart cards
  • Secure network systems
  • Laptop and tablet integration
  • Handheld and mobile devices

The U20-ASF-BT Developer Kit provides development tools, including an interface development board, software and documentation, to assist developers with the integration of the U20-ASF-BT. The Developer Kit also includes APIs and data conversion modules to help expand the capabilities of your fingerprint biometric system with the following functions:


  • Register, update and delete user profiles
  • Verify or identify user
  • Manage user database
  • Control system settings (brightness, exposure, gain, security levels, quality threshold, etc.)
  • Test all functions
  • Interface with PC and SecuGen USB fingerprint readers


U20-ASF-BT2 Developer Kit Components


  1. U20-ASF-BT2 + mounting bracket
  2. Development board with RS232 DB9 connector, LEDs, GPIO buttons and RESET button
  3. 9-pin Molex cable to connect to development board
  4. USB cable for 5V DC power (used with FMS option) or Host Linux PC for programming using TCP/IP over USB connection (used with Custom Application option)
U20-ASF-BT2 FMS Development Kit
(for FMS option)


The U20-ASF-BT2 Developer Kit for Fingerprint Management System (FMS) runs on Windows 11 / 10 / 8.1 / 7 to help programmers quickly and easily develop reliable applications based on the built-in Fingerprint Management System.


  1. SDATest Demo Program
  2. Sample fingerprint template database
  3. C# Sample Source Code
  4. Documentation
U20-ASF-BT2 Software Development Kit
(for Custom Application option)


The U20-ASF-BT2 Developer Kit for Custom Applications (SDK) runs on Ubuntu and Fedora Linux platforms and includes application source code to help programmers quickly and easily build custom applications based on U20-ASF-BT2. Development tools in the Developer Kit require Ubuntu Linux 14.04 64-bit or Fedora 23 64-bit development platform, with GNU tools installed.


  1. Ingenic MIPS cross-compiler tools
  2. Runtime libraries
  3. C/C++ Sample Source Code (Linux build environment)
  4. Documentation

A mounting bracket that holds the U20-ASF-BT2 module is available for purchase separately. The bracket allows for a consistent, secure fit of the module when integrating with your hardware.