ZFM-20 fingerprint capture library

ZFM-20 is an optical fingerprint sensor module series developed by Zhiantec. Resolution of these fingerprint modules are 256×288 pixels and depending on the module it can be accessible over UART or USB interfaces. Other than capturing fingerprints this module has inbuilt DSP to process and verify captured fingerprints.

This ZFM-20 fingerprint library is developed to capture and retrieve fingerprint images from the above sensor module. The main purpose of this library is to use ZFM-20 sensor with PC as a low-cost fingerprint capture unit and because of that, in-module fingerprint processing and verification functions are not implemented in this library.

ZFM-20 fingerprint sensor test setup with CH340G serial to USB converter.

ZFM20-LIB is x86 native shared library and it's implemented using Lazarus/FPC. This library is developed to use with most of the programming languages which including C, C++, Delphi, FPC, Microsoft .net framework based languages, etc. Object-oriented wrappers for this library are available for both .net framework support languages and for FPC.

This version of ZFM-20 Fingerprint capture library is tested with ZFM-20 series serial fingerprint module with CH340G USB to serial converter. Generally, this library is designed to work with any USB to serial converter which including FT232, CP2101, etc.

ZFM-20 fingerprint capture library is an open source shared library project and it's source code and compiled binaries are available at https://github.com/dilshan/zfm20-lib. This library is released under the terms of MIT License.

Comments

CD2003 - yet another simple FM radio receiver

In the last few days, we are looking for some simple FM radio receiver to integrate into one of our ongoing projects. For that, we try several FM radio receiver ICs including TDA7000, CD2003/TA2003/TA8164, CXA1019, and KA22429. Out of all those chips we select CD2003 (or TA2003/TA8164) based receiver for our project because of its simplicity and outstanding performance. Except to CD2003, Sony CXA1019 also perform well but we drop it because of its higher component count. We design our receiver based on Toshiba TA2003 datasheet and later we try TA8164 and CD2003 with the same circuit. Either CD2003 or TA8164 can directly replace TA2003 IC, and as per our observations, TA8164 gives excellent results out of those 3 chips. A prototype version of CD2003 FM radio receiver The PCB design and schematic which we used in our prototype project are available to download at google drive (including pin-outs of crystal filters and inductors ). Except for CD2003 IC, this receiver consist...

Arduino superheterodyne receiver

In this project, we extend the shortwave superheterodyne receiver we developed a few years ago . Like the previous design, this receiver operates on the traditional superheterodyne principle. In this upgrade, we enhanced the local oscillator with Si5351 clock generator module and Arduino control circuit. Compared to the old design, this new receiver uses an improved version of an intermediate frequency amplifier with 3 I.F transformers. In this new design, we divide this receiver into several blocks, which include, mixer with a detector, a local oscillator, and an I.F amplifier. The I.F amplifier builds into one PCB. The filter stage, mixer, and detector stages place in another PCB. Prototype version of 455kHz I.F amplifier. In this prototype build, the Si5351 clock generator drives using an Arduino Uno board. With the given sketch, the user can tune and switch the shortwave meter bands using a rotary encoder. The supplied sketch support clock generation from 5205kHz (tuner f...

Calculator for audio output transformers

Audio output transformers are heavily used in a vacuum tube and some (older) transistor base audio power amplifiers, but these days output transformer are quite hard to find and expensive item. For homebrew projects, the best option is to construct those transformers by ourselves and this script helps to calculate winding parameters for those transformers. This " AF output transformer calculator " script is written using Python and it works with most of the commonly available Python interpreters . The script is available to download at google drive under the terms of GNU General Public License version 3.0 . Homebrewed 25k: 4 output transformer Once supplied the input parameters this script provides a winding ratio, the number of turns required for primary and secondary winding and required copper wire gauges for both primary and secondary windings, etc. We construct several AF output transformers based on results of this script, which including transformers for M...