Saturday, February 23, 2013

Replacement Code Lock for LS7220 base Systems

LSI Computer System's LS7220 is a digital code lock system for automotive systems. This LS7220 integrated circuit is difficult to find in many places and because of that we design some alternative system which simulate the functionality of LS7220 code lock system. This simulated system executes on top of the PIC16F628A 8bit MCU and it release as an open hardware project.

LS7220 is a "hard-wired" code-locking system, but this simulated system provides both "hard-wired" and customizable (re-programmable) code locking options. This re-programmable feature provides some higher degree of protection to the system and it allows user/administrator to change system’s code at any given time by without changing the wiring layout(s) of the system.

Pinouts of Programmed MCU

In this project PIC16F628A MCU use its internal 4MHz oscillator and because of that it doesn't require any external clocking source(s). This system is design to work with 5V DC power supply and its output is interface with 5V - 12V relay to drive the locking mechanism(s).

Compared with the LS7220 the only drawback of this system is its limited supply voltage. LS7220 have some wide supply voltage range like 5V - 18V DC. But still you can couple this virtual system to that supply voltage by using some voltage regulation ICs like LM7805, LM317, etc.

The firmware of this system is written using Hi-Tech C and it is design with minimum external component dependencies. Because of that user can use "programmed MCU" with his/her own circuit design / customizations.

The main purpose of this project is to create some alternative design for LS7220 base code locking systems. Please note that this is not a project to degrade the features/specifications of LSI-CSI's LS7220 (or related) products. The complete project content including source codes and sample schematics are available to download at elect.wikispaces.com. All the content of this project are release under the terms of GNU GPL Version 3.0 license.

Monday, February 4, 2013

PT2399 base Echo Sound Effect Generator

This is an easy to build high quality echo sound generator and it’s completely based on Princeton Technology’s PT2399 echo sound IC. This supplied circuit is specifically design to interface with electronic musical instruments (e.g: electronic audio synthesizers, electronic organs, etc.) and with microphone systems.

This echo sound effect generator requires 12V - 25V DC power supply and it can deliver aprox. 20W output power (with 8Ω speaker and 20V - 5A DC power supply). This given design of echo sound generator has 3 main controls, such as echo delay adjustment, echo-effect mixer and master volume control. This delay and mixing ratio is heavily depended on input source.

Output of C1 note with maximum and minimum echo effects

At the testing stage we test this system with lot of input sources. According to our experiments this system can product good results with slow speed music and it produce excellent results with the voices. When it comes to high speed music (with maximum delay and mix levels) output seems to be bit noisy and distorted.

The complete schematic, PCB design, sample output files and output graphs of this system are available to download at elect.wikispaces.com. Please note that this supplied PCB is not tested by us, if you find any mistakes or have some suggestions about PCB design please drop us a mail.

Friday, February 1, 2013

nanoide – custom build tool with source editor

nanoide is an effort to build scriptable build tool with source code editor. Initially I developed this tool to test some of my ongoing compiler projects and later I extend it with source code editors and with simple UI.

nanoide build 138 with sample build script

nanoide build system is based on FreePascal style scripting system and it comes with more than 50 inbuilt support functions. With help of nanoide, users can create complex conditional build flows and it helps to automate system testing processes also.

Current version (build 145) of nanoide editor support C/C++, Java, Pascal/Delphi/Lazarus, Python, HTML, XML, CSS, Perl, Basic/Visual Basic, SQL, Tex, DOS batch scripts and UNIX\Linux shell scripting. nanoide is developed using Lazarus and it can be compiled and execute on Windows, Linux and Mac OS platforms. Virtually nanoide is compatible with any command line-driven compiler and it is tested with TinyC Compiler, Lua, Python, FPC and with PHP


nanoide build system and source code editors are release as an open source – free software under the terms of MIT license. Latest nanoide source codes and executables are available at sourceforge.net – nanoide project page.