FEB7
GSM Phone Jammer Circuit Schematics
Here is a very simple plan to make a "dirty transmitter" that is also known as Cell Phone Jammer.
It is based on NE555 as simple noise-maker whose output is fed to a single transistor oscillator. The oscillator is designed to operate between 800MHz and 2GHz which happens to be the frequency span used for GSM phones. The frequency of operation is set with a trim-capacitor.
The battery should last no longer than 1 hour and the range of jamming is around 10-15 feet.
Source: Laszlo Kirschner
JAN11
SparkFun Free Day 2012 - free 100$ stuff
Once again, it is that day of the year when SparkFun Electronics is having what they call a Free Day where you have a chance to get $100 worth of their products for free - you will pay only for the shipping.
All you need to do is show up at their website at 9 AM Mountain Time on January 11th, 2012 to try your hand at winning! If you are not registered yet, do it now, because once the event starts it is very hard to navigate throught their website because of all the traffic they get.
To know the rules and howto, watch the video after the break.
Source: SparkFun Electronics
JAN10
Web server maintenance
Dear visitors of Elektronika.ba web portal, from 01-09-2012 to 01-10-2012 web site will be offline due to maintenance of web hosting services.
Thanks for understanding!
DEC20
Prank Gift Box
Many people have a habit of shaking gift box in order to figure out what's inside prior opening.
[Jason] decided to have some fun with those kind of people by adding a shake-activated sound player inside the gift box. He bought a simple audio recorder/player module from Radioshack and created a simple shake-sensor with two pieces of wire and glued everything together inside of a present box.
Make sure to see the video of this contraption.
Source: DIYHacksAndHowTos
NOV17
Brute Force BIOS Cracking
Cracking BIOS passwords is usually done by reading a BIOS chip with a programmer and extracting the password from it. There is another way to do it and that's by using a brute-force method. This method doesn't always result in finding the password and takes a lot of time.
So, someone figured out how to automate the BIOS brute-force crack method by using Arduino (AVR) to emulate USB keyboard and by sniffing on VGA output from graphics card to test for a certain pixel on screen when the password is entered correctly.
Schematics and source code are available for download on project page.
Source: alfersoft.com
OCT26
Nixie clock - Millivolt Meter Hack
After finding an old Nixie Millivolt Meter on some pile of disposed electronics, [Jimmy] was wondering how to make a clock out of it but still preserve the original voltage measuring functionality.
This instrument shows voltages in 0-99.99mV range (0-0.0XXXXV) on Nixie tubes so [Jimmy] had a great idea to generate the appropriate voltage on its input pin that will correspond to current time. For example, to show time at 12:15 he must generate exactly 12.15mV. Voltage generation is done with PWM signal from an Arduino AVR microcontroller.
Source: Jimmy H.
OCT17
Linear and Non-linear Circuits
There is another great video-tutorial at "The Signal Path Blog" and this time it is about linear and non-linear circuits.
"The source of a non-linear input/output characteristic is presented in three different domains: mathematical, time domain and frequency domain. After the theoretical discussion, a sample circuit is built and tested to illustrate real time signal distortion."
This tutorial is an absolute must-see because it is full of useful information and practical real-world examples.
Source: The Signal Path Blog
OCT6
PIC16F883 Development Board
So far we have seen a few DIY development boards for both PIC and AVR microcontrollers.
Now we can see a pretty minimalistic dev-board for PICs that has a LM1117 linear power regulator for 3.3V or 5V choice, PIC16F883 with 7kb FLASH memory and a few pin headers on the other side. All I/O pins of MCU are accessible on those pin headers and there is also an ICSP port for PIC programming.
The board definitely has that clean look and could be very useful.
Source: Phil
