Dilshan R Jayakody’s Web Log

This is an easy to build " high-bright LED" night light, which I was design and developed in weekend to replace my existing 5W ( filament base) night lamp.  This circuit is mainly based around TL494 PWM driver IC and LM350 - 3A adjustable voltage regulator. The LED used in this project is 9V - 10W high bright LED and this given design is capable to drive maximum of six, 10W LEDs. Microscopic view of 10W High Bright LED with controlled input This unit is design to work with 12V to 30V DC power supply and it can withstand for voltage fluctuation around 12V to 35V. The schematic of this unit is available at upvater.com under the terms of CERN OSH 1.1 License .

This is a simple project to demonstrate the USB custom hardware interfacing with Unity3D game engine on top of Microsoft Windows operating system(s). The custom hardware unit used in this demo is build around Microchip’s PIC18F2550 MCU. This custom USB controller consists with 4 push buttons and linear potentiometer. In supplied demo user needs to control aircraft with those buttons and potentiometer. According to the game logic 4 buttons are used to control the flying direction and flying angle of the aircraft and potentiometer is used to control the speed of the aircraft. System's host environment consists with 2 main applications such as Session Controller and Unity3D game . Session Controller is responsible for USB communication and data conversions. It’s a native application written using Delphi and it gets started with Unity game project. Communication between Session controller and Unity game project is happening through OS level shared memory location. ...

In this post we introduce brute force attacker for Sudoku puzzles. In title we say " classical " because it operates in a traditional " dictionary base " style. This terminal application is design and tested on Linux base systems and it can capable to solve any symmetrical Sudoku puzzle up to dimension of 9×9. The primary objective of this application is to get some performance readings on some x64 configurations and initial version may not support external maps. Later I extend it to support with user defined maps and now it can handle up to 9×9 data matrix with at least one known value. The attack database (dictionary) is based on text-files with sequential access controller and it helps to reduce to main "system memory" consumption. Working order of Brute Force Attacker The performance of this application is based on system architecture (especially with RAM and auxiliary storage architecture), process configuration (such as process priority, me...

Smart Audio Box (SAB) is microprocessor controlled audio switch and amplifier system, which is specifically design for audio composers and for audio engineers. SAB consist of 4 high impedance stereo inputs and two output modes. One output mode can drive stereo headphone/earphone and other output mode can drive pair of 8W speakers. In prototyping stages we identify those modes as " Personal Mode " (headphone output) and " Audience Mode " (power amplifier output). Another main feature of this system is its programmable 16 step attenuation controller. This attenuation controller helps to control the audio output level of each output-mode. Prototyping version of Smart Audio Box The main component of SAB system is ATmega8 MCU, other than that headphone amplifier is design around NJM4556 high current operational amplifier and power amplifier is based on TDA1521A. To operate, this system requires 2 power sources. Microcontroller, ADC interfaces and CMOS logic-s...

Adjustable dual-rail power supply is an essential utility for analog electronic experiments. In this post we illustrate extremely simple, adjustable dual-rail power supply using LM317 and LM337 voltage regulators ICs. This PSU delivers 2A ±1.35V to ±18.5V output and thanks to 3 turn linear potentiometers output can be adjustable up to 2nd decimal point. Wiring diagram of dual-rail PSU The PCB of the PSU is simple to design and compact (65mm × 50mm). Both LM317 and LM337 need at least 60mm × 55mm or larger heat sinks (and both of these heat sinks need to be electrically isolated). The PCB and schematic of this PSU is available to download at here .

Intel HEX is an open file format to save machine code data. Today lot of compilers and EEPROM/Microcontroller programmers support for this file format as de facto standard. hex2file is a lightweight, command-line driven application to view and convert Intel HEX files into other file formats. I developed this application as a supporting utility for our on-going compiler/virtual machine projects. This utility supports four output formats which include CSV, plain- text, binary and numerical-text. hex2file standard numerical output in screen mode hex2file is an open source - free software and its available for both Linux and Windows operating systems. The latest version of hex2file utility is available to download at sourceforge.net – hex2file project page . The more details including project documentation are available at hex2file.sourceforge.net .

Nichrome-Wire Cutter is an essential tool for model aircraft constructions. We mainly use Nichrome-Wire Cutters to fabricate model aircraft wing assemblies, other than that Nichrom-Wire Cutters are used to cut wax, polystyrene materials and other similar kind of materials. In this project we construct electronically Controlled Nichrome-Wire Cutter. The main feature of this cutter is its (non mechanical) variable temperature controller. The temperature of the Nichrome-Wire is controlled using TL494 PWM controller. In this design TL494 is oscillated with fixed frequency and only varying factor is its duty cycle, in this given design R2 is used to control the duty cycle of the frequency. Duty cycle variation with R2 potentiometer This Nichrome-Wire Cutter requires 8V to 20V – 3A DC power source and 16.5V – 3A is recommended supply for this system. When constructing this system makes sure to solder and connect all the components properly, improper connections may cause oscillatio...