Instructables user [cedtlab] has posted an interesting LED project that simulates birthday candles. The circuit runs on an AVR ATTiny45, and is powered by 4 AA or AAA batteries. By using a Charliplexing technique, they are able to drive all 20 LEDs with only 5 pins of the ATTiny. A thermistor is used for detecting breath by measuring temperature changes, and then blocks of LEDs turn off depending on the change detected. They have provided schematics and source code for everything. Make sure to check out the video of the “ficticious birthday party” after the break.
Misc Hacks4177 Articles
Portable Air Conditioner
The dog days of Summer are looming just over the horizon like a hot sticky wave of impending doom, but you don’t have to take it lying down. Building a portable air conditioner is cheap easy, and we daresay refreshing.
You’ll need the following materials: a condenser, heater core, or radiator, a styrofoam cooler, a submersible water pump, a few case fans, some adapters to power the works, and a few other materials. The pump circulates cold water through the condenser as the fan pushes air through it and the rest of the box.
We’ve never been huge fans of swamp coolers like this one since they offer no true refrigeration cycle. What’s more, they pump a good deal of humidity into the air, which makes the heat worse in the long run, or creates a vicious cycle of cooling and humidifying. Still, when the heat is scrambling our brains, it’s hard to say no to any relief, however ephemeral.
Magnetic Movie
Magnetic field lines may be invisible to the naked eye, but they behave in ways that would amaze us if only we could see them. [Ruth Jarman] and [Joe Gerhardt] from Semiconductor wanted to make them visible for everyone, so they produced Magnetic Movie, a film that combines animations, theoretical models, and actual VLF recordings of the entire Earth’s magetic forces to create a film that shows magnetic fields moving and jumping through the air in living color.
The film is part art project and part scientific experiment, but we can enjoy it on both levels, as watching the path and motion of magnetic field lines is both beautiful and informative. Get a glimpse for yourself after the break.
Taser Ammo For Your Spud Gun
We definitely don’t recommend trying this one, but [Tony] sent in this odd twist on the old potato launcher. A pair of physics students put together a Taser like potato sized bullet. On impact, two metal pins are inserted into the target, delivering an electric shock. Depending on the size of the capacitor and amount of charge delivered, it can be a (sort of) non-lethal or lethal shock. We’d prefer not to be shot with either one.
[via pspmod]
Live Full Motion Video On A Peggy
[Windell] was stoked enough to send us [Jay]’s sweet hack on [Windell]’s Evil Mad Scientist Laboratories Peggy 2.0 kit. [Jay] added serial input and hacked quartz composer on his mac to light up all 625 LEDs with live motion video. If you were jealous of the Metalab’s giant LED display, now you can have your own – smaller and cheaper.
EMSL has recently supplemented this awesome device with their Arduino Library for Peggy 2.0. It is a program library that contains various animations and demonstrations of how to draw on a Peggy. Download and enjoy them as they are or tweak them to test out some of Peggy 2.0’s capabilities.
Pet Photography And Tracking
We’ve seen numerous products geared toward tracking the location and activities of your pets, two in the last month, but we feel sure you can make more functional devices than those you can purchase. Let’s look at a few and consider our options.
Touchkit – IR Multitouch Screen
If you’ve got an extra grand laying around, you can pre-order one of [nortd]’s touchkits. It features a unique custom made acrylic screen with a crap ton of IR LEDs embedded in it. An included IR camera provides the input and a projector (you get to supply your own) is used to light the surface. We mentioned this in our multitouch roundup and you can find a video of it embedded after the break.
