Month: October 2007

$25 Head Mounted Display

October 7, 2007 by 29 Comments


[Jake] sent in his source for a cheap head mounted display. In his writeup he notes that the spy video car comes with quite a pile of handy electronics – video tx/rx, camera and this simple black and white monocle head mounted display. (Which happens to be available as a replacement unit for a mere $20) The screen is a Kopin 300M (Black and white, 300×240 pixels) The display is actually somewhat usable out of the box, but he takes the time to note some simple mods that’ll improve the displays performance.

If you ever bought a virtual boy just to gut the display, then you know you want one. In fact, I’ve got a perfect project in mind for this particular toy.

Back From Belize Extra

October 6, 2007 by 12 Comments


Yesterday, I was standing on a tropical island off the coast of Belize. Vacation rocked with lots of SCUBA diving, spearfishing and snorkeling. I’m back home, shaking off the jet lag and clearing up my inbox. Thanks to [fabienne] for filling in and letting me unplug for a while!

[Darkrom] has set a new standard for Hack-A-Day readers… I haven’t seen it in person, but that looks like a legit Hack-A-Day tattoo.

[null] sent in a new use for a frequency generator, a spare car amp, a sub-woofer and a plastic coffee can – brass cartridge polishing.

[LoopyMind] sent in this Game Boy Advanced Movie Player IDE hack. It’s pretty much a direct CF to laptop drive cable with an external battery supply.

[Dingolishious] sent in a POE UPS/remote power control solution. Could be handy if you’re using many POE devices, or if you’re having power issues. He added an inexpensive remote power monitor/switch solution behind his UPS. It senses power outages and kicks out an email – and allows remote power cycling of his POE devices. Of course, if you’ve got a linux box behind the UPS, it can monitor the output from the UPS and send notifications.

[William] added a preamp stage to his iKEY usb recorder. looks like an interesting toy – it’ll record audio directly to a USB flash key. The pre-amp allows him to record in more challenging environments.

[Andrew] noted a simple mod to increase the deadly fire power of the ubiquitous airsoft pellet gun. It’s just a matter of reducing some extra space in the spring compression area.

Last but not least, [VIPER] modded his projector to use a 12v halogen headlight bulb. Not a bad idea – at one point I was pondering a 550 watt source four halogen as a possible replacement.

Roasting Pan Audio Amplifier

October 5, 2007 by 17 Comments

When you need a rigid, vibration-free chassis for your amplifier, look no further than a roasting pan. I’ve used cast cement for subwoofers, but using a cooking pan bolted to a heavy wooden chopping board is a cheap way to get a rigid surface on which to build audio gear. The amp circuitry used by [Mark] is not complex, but it gets the job done. The “oxygen free copper cable” and “pure silver wire” are not needed, just make sure you have a solid mechanical connection. In other words, just tin your wires, bend small “u” shapes at each end, hook them together, and apply solder to the heated ends. Alternatively, hold the ends of stranded wires parallel to each other and twist the ends together before tinning, then solder. Test everything with a multimeter while moving wire joints to make sure you have no weak connections. Now you won’t waste your money on hyped-up cabling materials.

Thanks to [Gio] (who seems to have some personal audio projects as well) for the tip.

Build Your Own GPS And GLONASS Receiver

October 4, 2007 by 17 Comments

[superlopez] sent in this detailed article (mirrored here and here) which describes how to build a GPS and GLONASS (the Russian version of GPS) receiver. The resulting device is gigantic compared to one of those tiny bluetooth USB GPS units, but the ability to build one’s own receiver is one of those post-apocalyptic skills I sure would like to have. The creator of the article [Matjaz Vidmar] aka [S53MV] also has pages on Packet-Radio (PKT) transceiver improvements (PKT gets my vote for the best post-apocalyptic technology, and the only believable technology featured in the Transformers movie), and a more sophisticated homemade frequency counter than the one featured earlier this summer.

In 2005 we featured a from-scratch GPS receiver as well, thought the project site seems to be down. If your GPS unit just needs a better antenna, check out [Will]’s how-to from last year.

Breathing Walls With Shape Memory Alloy Wire

October 3, 2007 by 8 Comments

When you need something quietly bending or moving, don’t underestimate SMA’s (or Shape Memory Alloys). The Living Glass project by architects [David Benjamin] and [Soo-in Yang] catalogs an experiment in building interactive, flexible, “breathing”, walls out of SMA wire and microcontrollers. Although they use Basic Stamps, the project could easily be extended to more cost-effective microcontrollers for large surfaces. The project is well documented with videos (AVI) of each prototyping step and even includes the ideas that were ultimately scrapped. Even if you don’t build a wall of interactive gills, this project should give you plenty of ideas for uses of SMA wire embedded in semi-flexible materials.

Interactive Textile Construction

October 2, 2007 by 4 Comments

The e-textile construction kit by [Leah Buechley] consists of stitch-able sensors and microcontrollers. Stitch-able refers to the fact that these parts can be sewn with a needle and thread into wearable clothing or other fabric-based housings. A paper (PDF) on the e-textile construction kit project contains the first version. The second version of the e-textile construction kit, the LilyPad Arduino, is available this month through SparkFun’s site. Especially interesting are her instructions for modifying the clock speed on the Arduino to make it suitable for battery powered wearables.

We’ve covered [Leah Buechley]’s work twice in 2005 for her wearable led matrix work.

Update: [Leah] updated her site since we posted this and added this new how-to.

OpenBeacon: Active RFID Platform

October 1, 2007 by 10 Comments

The OpenBeacon project is an open source hardware and software active RFID device. OpenBeacon tags consist of 2.4GHz transceivers and a PIC16F684. One use of the project was to create CCC Sputnik to show the downsides to information culled using data mining from large tracking systems. People who chose to participate and wear the Sputnik tags did so voluntarily to create a database of material for further study. The hardware schematics (PDF) for the first version tags as well as the firmware for all versions has been released. Further creative uses of the OpenBeacon project are strongly encouraged.

As a reminder, the 24C3, the 24th Chaos Communication Congress, call for participation ends on October 12th. The theme this year encompasses all hardware projects and more specifically, steampunk themed submissions. Check out the CCC events blog for more information.