Dilshan R Jayakody’s Web Log

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...

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 8 Ω 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 ma...

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 .  ...

This post is about simple Atmega325 development board which I was designed and build to test some large AVR systems. This development board contains ATmega325 MCU and MAX232 base RS232 driver/receiver unit. Thanks to SMD packages and components dimensions of this board get limited to 85mm × 62mm. This development board requires 5V external power supply and all its external circuitries (RS232 driver and hardware CPU reset) can be enable/disable through on-board jumpers. ATmega325 Development Board PCB design of this development board supports only for ATmega325 - TQFP64 package and MAX232 - SO16L package. This ATmega325 Development Board is release as an open hardware project and all its design files are available to download at google drive .

LEDShoot is a simple electronic shooting game which we developed in a year end vacation period. This is a single player electronic game with following game play logic: There are two fighting groups are exists in this game world. RED group is an enemy group and GREEN s are friendly parties. Player’s job is to shoot the RED group(s) when they appear on the stage. Player gets limited time to shoot and misfires are treated as negative points. When player get 100 points game get end with winning message. This electronic game system is mainly based on ATmega32 MCU and firmware is developed using GCC C (with Atmel Studio 6.0). This system is design to work with 5V - 1.5A power supply unit. We developed this system as a hobby project and we construct it on a couple of breadboards, at the moment we don’t have any PCB design for this project. When assembling the circuit make sure to use some heavy-duty push button for ( SL2 ) control key. For ( SL1 ) use 8 Ω - 1W (60mm) sp...

PalindromicGen is a lightweight configurable tool to perform reverse-and-add operations to obtain Palindromic numbers . The main purpose of this application is to examine the existence of Lychrel numbers in a series of natural numbers. Sample execution of PalindromicGen from 10 to 1000 base numbers This tool is developed using Free Pascal compiler and its design to work with many platforms with minor adjustments. We test this tool in several Windows and Linux distributions. PalindromicGen is design to work with Pentium 4 (or compatible) instruction sets (under the default compiler configuration) and its performance is heavily depends on its settings and system configuration. Under the theoretical limits this application can manipulate up to 2 31 digit numbers and at the development phase we test this system with maximum of 501 digits (to obtain the palindromic number of 1186060307891929990 ). PalindromicGen is an open source software project and it is release un...

This is a "quick design" to make surround sound dock for Apple iPod, iPhone and iPad devices. This audio docking module contains analog surround sound processor, bass booster and electronic mode switch. Main components of this surround sound dock are LA2610 - analog surround sound processor and ATTiny13 - 8bit MCU. This unit is design to work with 9V external DC power supply and it can deliver maximum of 2 × 1W audio output power. Printed Circuit Board Design of Surround Sound Dock In prototyping stage we test this system with couple of Apple iPod and iPad devices with 4inch full range 8Ω speakers. This system can also drive professional headphone through its " Ext. Output " connector. This system need 160mm × 100mm double side PCB and it is specifically design for vertical docking chassis. This project is an open source hardware project and its design and other related materials are distributed under the terms of Creative Commons - Attribution...