Embedded 1 to 8 intercom system

This project was created by M.Shakeel Malik. System allows to make regular calls and to one of 8 internal phones.   System is controlled by Atmel AT89S51 microcontroller. System also have its own tone generator which allowing to send dial and busy tones. Calls can be hold with voice message or melody signal transmission. Circuit and source asm code is available. Continue reading

High power RGB LED controller

This is nice project from petesworld. Device is used to drive high power RGB led (250mA) by using PWM control. Controlling separate colors (Red, Green, Blue) there is possible to generate up to 16 million colours. Device is used mainly for dynamic and static color effects.   LED was placed in to diffused dome lamp. This way diffused light looks nice. Circuit diagram isn’t very complicated as there are ZXLD1350 current drive circuits used. Source code is available for non commercial use. Be sure to check for other project revisions. Continue reading

Handheld pocket health monitor

This health monitor may become a dream of many people while it is capable to monitor most of human bio-signals including ECG, EMG, GSR, Pulse Oximetry, Temperature, Breathing sounds and even movement with 3 axis accelerometer.   This health monitor is based on Texas Instruments MSP430 MCU which is characterizes as low power microcontroller. Data is sent via blue-tooth to Pocket PC where data is analysed and displayed as graphs. Also data is recorded to dataflash for backup. Continue reading

DIY AVR tetris game

This is simple tetris game clone developed by Johannes Treu.   The game consists of separate boards: one for LED display where 240 LEDs are aligned one for Atmega8 microcontroller board with other circuitry and pushbutton board. The idea looks nice-feels like I want to play the game couple times. If you want too, then go ahead. All files are available at avrfreaks site or you can download circuit and source here. Continue reading

AVR dot-matrix LED game

This simple game console if we can say so is built under AVR Atmega168. Game display is made of 16×16 dot matrix LED.   Game platform has many variations and upgrades line interfacing to TV, AT keyboard, LCD. Author also provides nice collection of ready to play games for free including “Space Fight” , “Super car” and others. Continue reading

PIC based multifunction waveform generator

Luhan Monat have various hobby circuits mostly based on PIC microcontrollers. One of then that catches the eye is function generator which is capable to generate sine, triangle, saw, burst, sweep and noise signals.   In his design he used PIC16F870 and R2R resistor ladder as DAC output. He stored signals in lookup tables 256x8bits. Running at 20MHz generator is capable to give clean 60kHz (1Hz accuracy) sine-wave adjustable in 1, 25 and 500Hz steps. Because of limited performance he only used three LEDs indicating which waveform is used and another three LEDs for step rate indication. Author includes circuit, source files. Continue reading