GPS and temperature logger on PIC

This project was intended to be used in weather balloon which logs position and temperature data read from LM75 temperature sensor. Device has 64kB EEPROM memory for storing data.   Device position can be sent via SMS by using mobile phone. Also there is ability to connect and control devices with relay. All project files are available for download. Continue reading

Electronic door unlocker

Dheera Venkatraman have decided that using keys is boring and obsolete. So he managed to build electronic door unlocker.   He used PIC16F630 microcontroller attached to PS/2 keyboard and stepper motor to slide the head. Keyboard is placed outside the door. When 5 correct numbers are pressed – the door unlocks itself. Circuit and C program is available if you want to modernize your college dorm room. Continue reading

10MHz function generator based on AD9835

Signal generator is must have tool on your working table. Buying one may be too expensive especially if you are hobbyist. So why not to build one. There are many generator chips available. One of them is Analog Devices AD9835 Direct Digital Synthesis (DDS) generator chip which is capable to generate sine wave up to 50MHz.   This signal generator is programmed to output frequencies from 1Hz up to 10Mhz with 1 Hz step resolution. Generator is controlled with three pushbuttons while information is displayed on one sliding window LED display. DDS generator is controlled via PIC16F628 microcontroller. Continue reading

Propeller clock project

Bob Blick have built this propeller clock some time ago, but it still serves as an example for other modifications.   A motor spins the “propeller”, and a PIC16F84 microcontroller keeps track of time and changes the pattern on seven LEDs with exact timing to simulate a 7 by 30 array of LEDs. Moving led array makes illusion of flat image. Author provided all necessary material including circuit, PCB, and source code that may help to build it for everyone. 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

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