Kipkay writes -
First time in the world a blu-ray laser from a Playstation 3 has been installed in a Star Trek Phaser! Build one yourself for around $100. I “Boldy go where no man has gone before”! Watch the video and then follow the Steps to build your own!
DIY Blu-Ray Laser Phaser! - [Link]
TeleChrome writes in with a Flickized iron transfer how-to on making your own PCBs -
How to make professional-quality printed circuit boards right in your kitchen sink: This remarkable technique uses an ordinary laser printer to transfer a toner resist mask onto a piece of plain copper clad
Electronic prototypes - [Link]
Chris made this excellent tutorial on creating a VGA test box with a PIC microcontroller. He writes:
For quite some time I’ve been wanting to create a device that outputs VGA signals. My main goal was of course to be able to display whatever I wanted on the monitor I was currently using. The goal of this project is to create a device that is capable of outputing VGA signals to a CRT monitor in order to display figures, text and characters. This will be done using a Microchip PIC microcontroller at 4 MHz clock speed. The programming required to achieve the VGA timing signals must be done in low level assembly because of the high level of precision that is necessary. The hardware assembly is just basic buttons, switches & wire that you can purchase from local electronics stores.
Simple PIC VGA tester - [Link]
Drawing the Whole Schematic
Why draw out the whole schematic? Because I had no idea how the sensor element worked. I wasn’t rapt to know how some unknown manufacturer had designed an alarm circuit; I simply needed to know how to work the sensor. With no part number on it and no knowledge of the field of gas detection, the easiest method seemed to be to see what the original circuit did and make guesses about the sensor from there.
In retrospect, everything I need to know about the sensor I could have figured out with my multimeter instead of figuring out the circuit rather than after figuring it out. But no harm done.
Reverse-Engineering a Flammable Gas Detector - [Link]
Bi-color LEDs are same LEDs as uni-color just there are more than one LED housed in one package. Bi-color LEDs may have two or three leads depending on intentional connection method.
Three lead LEDs have common cathode lead to which both LEDs are connected internally.
Bi-color LED indication - [Link]
This is the second in a series of articles about generating sound with an Arduino [First Part here]. The first article covered the various methods available for sound generation with an Arduino. In this article we take a small step; “Hello World” for Arduino sound. We prepare for our future experiments by hooking up a PC or powered speaker so we can hear the Arduino sing.
Arduino Sound Part 2: Hello World - [Link]
This device works with dial tone (DTMF) protocol. And its working depends on your phone company. If it sends phone numbers to call recipient that it is OK. The device simply detects and analyses phone line activity and detects incoming callers phone number which then is stored in EEPROM memory.
Device can remember up to 10 phone numbers in PICs EEPROM memory. Numbers can be erased at any time. Project files are available for download.
PIC based caller number identification - [Link]
There are many time servers around the world that provide reliable time by using NTP (Network Time protocol). Everyone can connect to these serves and receive exact time via this simple protocol. Read more about how does it work in http://www.pool.ntp.org/.
Guido Socher from tuxgraphics.org has built nice simple NTP client that can request for time packets from server and display this data on LCD.
He used one of his AVR ethernet boards where simple server application allows easily configure clock settings like NTP server address, time offset, Clock address and more. The web server has also a second page where current time is displayed – the same as on LCD. Author provides ideas on how to build clock, ad even provides source code, but if you just want to have this clock on your table really fast on then buy a kit from http://shop.tuxgraphics.org/and support Guido for his nice ideas.
AVR Network Time Protocol Clock - [Link]
This is very simple countdown timer implemented on 89C2051 microcontroller. One button is used to set time up to 99 seconds, another is for starting timer. Time is displayed on two 7 segment LED displays. Buttons and display scanning share same pins so algorithm has to check buttons and display time on LED displays in a row sequence. Source code is included that allows to modify program and compile.
Very simple countdown timer with 7 segment displays - [Link]