[drj113] posts his cool word clock. After seeing a similar clock on an industrial design website, he set out to make his own version. He made custom pcbs with the toner-etch method. The front is a solid piece of copper clad board and the light shines through the etched areas. It’s powered by a PIC microcontroller and uses approximately 120 ultra bright LEDs. [drj113] has all of the circuit board diagrams, silkscreens, etch negatives, and code on the intructable so you can build your own.
Word clock: tell the time with words
Open garage door indicator
How many times has this one happened to you? Just coming home from work, you walk in from the garage, settle down, and pick up the newspaper. But wait, did you remember to shut the garage door?
Presenting the open garage door indicator. [xjc2010] chose the simplest circuit possible, using only a switch to turn on and off the setup, an LED acting as the signal, and a transformer/resistor combo to drop the voltage to an acceptable LED friendly 2.8 volts. We don’t like how he strung wire all over his house to place the beacon, and would have…
Touch sensitive keypad
[Viacheslav] built a keypad that uses human capacitance to detect key presses. Unlike normal keys which close a physical connection, his project detects touch through the PCB substrate. He uses the ADC capabilities of an AVR ATmega8 to measure a change in capacitor charges for each sensor in the keypad.
He’s posted the schematic, Eagle files, and source code with his writeup. He also points to a document on the theory behind this: QMatrix Technology White Paper (PDF). We’re impressed at how simple the circuit is: a microcontroller, capacitors, resistors, and a homemade PCB.
Software pulse width modulation
Pulse Width Modulation is a topic that tends to give a lot of beginners trouble. [Daqq], whose nixie plasma ball we covered a few days ago, has a simple but effective PWM project that you should take a look at. The circuit used 9 LEDs clustered together into 3 sets of RGB modules and connected them to an AVR ATtiny2313 through some current limiting resistors. Most of the time the PWM function of the AVR’s timers would be used to generate the signal but this application calls for 9 signals which is more than can be produced by this…
Build your own joystick
What can you build with a ballpoint pen and some extra parts? [gzip] found himself with a bonus box of right angle switches and other miscellaneous parts and set out to build a joystick. Simple arcade joysticks use switches that are actuated by the movement of the stick and this design embraces the concept. The four tactile switches are mounted on protoboard facing each other with part of a ballpoint pen in the middle. When the pen is moved it presses against one or more switches to close, completing a circuit. For good measure he even incorporated a fire…
Router/Twitter/Arduino clock
[Kyle] decided to build the above LED clock for his church. Though it may look impressive enough, it is also hiding loads of features. [Kyle] wanted to make the clock as easy to control as possible, so rather than use buttons or dials to control what is being displayed, he used Twitter. The clock is connected to the internet through a Linksys WRT54GL. The router was hacked so not only does it supply the connection to Twitter, it also parses all of the replies the clock’s feed gets. The clock responds to commands to turn it on or off, run a countdown before service,…
Using MatchBox cars as a switch
[atduskgreg] posted this interesting setup to flickr. He’s using two toy cars as a switch. He has wired into their metal undercarriages so when they collide, the circuit closes. We’ve seen some pretty nifty home made interface items, but usually they are posted with a clear purpose or a project. This one is a little puzzling. Does he intend to keep using the cars or was he just fooling around? Is he working on a toy that does something when they crash? Was he merely bored and wanted to see what he could attach to his Arduino. We may…
Color changing paint display
We’ve seen several creative projects from [Sprite_tm] and this one sets a new bar. He got his hands on some paint that changes color with temperature. By covering a circuit board with the paint then heating the circuits he’s created a heat actuated 7-segment display (his post is in Dutch). One second at 3 amps is enough to turn the black paint white. When the segment has been disconnected for about one minute the paint fades back to black. Now that we’ve seen his concept, leave a comment and tell us how you’d use it.
Disabling your cell phone’s mic for security
[Dan] set up this simple cell phone hack to disable his microphone when he’s not using his cell phone. He had read that the government can listen to you using your cell phone, even when it is off. This concerned him enough to hack into his phone. He removed the expansion port and wired the microphone to a magnetic reed switch. A strong magnet located in the screen side of his flip phone opens the circuit when he closes the phone. He notes that you could always just pop the battery out of your phone, but then you are…
How to build a life-sized electronic game
We’re very impressed with [Steve's] Electronic Snowball Fight game. It consists of two life-sized players standing opposite of each other. Each can throw a snowball or duck, the object is to hit the other person and not get hit yourself. He’s utilized a lot of good building techniques that could be easily adapted to other types of game play.
For the outlines of the players, [Steve] took pictures of himself standing, ducking, and in a throwing motion. Each picture was used to generate an outline which was then stenciled onto some Masonite. He then drilled holes along the outline…
Top 10 iPhone apps for electronics hackers
There are so many apps available for the iPhone, one might even say there are a plethora. We would like to take a moment to help you find a few that might help with your hacking projects. Ever have problems remember a formula when you need it? Need to track the acceleration of your brand new rover? How about beginners needing help remember resistor codes. Well, there’s an app for that. Check out our suggestions after the break.
Here at Hack A Day, we are strong believers in frugality. We think most hackers are. With that in mind, lets…
Circuit board instrument
[Moldover] decided to change up the way CDs are packaged for his album release. Yes, you still get a CD with some pretty sweet music, but the case can also play sounds. He custom printed a circuit board containing some LEDs, buttons, photoresistors, and what looks to be a piezo transducer which all combine to produce a strange whine like noise. But with the included headphone jack, he shows it can be used to produce some very interesting music – reminds us of circuit bending.
[Thanks Ferdinand]