Missile Command On IPhone With Real Missiles

[Jeff] and his team completed this iPhone controlled rocket launcher as part of their final project at Georgia Tech. Two servos provide the rotation referenced by an onboard electronic compass, and elevation control for launch. These are interfaced with an eBox 2300 using a few Phidgets boards.

Check out the launch video below. It’s too bad that they went with a commercial solution for servo control rather than building it themselves (especially considering it is an embedded systems class). But it is a nice build none the less. Now they need to add some imaging equipment to the rockets and they’ll be in business.

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Punching Out Parts

If you’re more of a code monkey than artist, it may be tough to transform your ideas into the 3D models necessary for fabbing. The folks working on openSCAD apparently feel our pain.

openSCAD uses a language somewhat reminiscent of C for creating models. A preview of the model is rendered alongside your code. Fully cross-platform, it runs on Linux, OS X, and Windows. Much like SketchUp, openSCAD can also extrude 2D outlines into models. This feature comes in very useful if one already has a set of technical drawings for a part. With no price tag, it’s pretty affordable during this costly season.

C-clamp Current Monitoring

[Hydronic] did some tests to make his own current sensor using a c-clamp wrapped with wire. He tried several different cores including an aluminum carabiner, the C-clamp, and what he calls a u-lock (removable chain link). There is some success here that could be improved with cleaner winding and by adjusting readings based on the length of wire used in the wrapping.

This did make us perk up a bit right off the bat. Reader [Mure], who tipped us off about this, suggested that this could be used to make your own Kill-a-Watt without including it in the circuit. We made the jump to house monitoring. We’d love to have a data tracker for our home circuits to curb wasteful energy use. Perhaps we’ll try to make our own sensors and produce a diy Cent-a-Meter.

Hacking ZigBee Chips: CC2430

[Travis Goodspeed] took an in-depth look at the debugging protocols for some ZigBee chips and posted his findings. In particular he’s looking at the CC2430 System-on-chip. These chips have a debugging protocol that is not hard to implement if you know what you’re doing. Certainly his tips make it easier for the rest of us. Don’t miss the info about reading from, writing to, and overcoming security of this hardware.

Aural Twitter

[POTUSCamacho] listens to his @public_timeline rss feed. In part one of his project, he describes creating a bash script in which he uses cURL get his private feed, sed to clean it and eSpeak to output a WAV file. In parts two and three, he goes on to discuss how he created an audio stream (currently down, opens in a new window) of @public_timeline and how he plans on tweeting vocally.

Better Resistors From A Pencil

Many of us here in the office (myself included) can’t tell the difference, but the audiophiles out there who want the best sound from their resistors should check out [Troel’s] write-up for making your own non-inductive graphite resistors. Graphite resistors have the traits for being non-inductive, have a negative temperature coefficient, and supposedly sound better. We liked the detail of his tutorial and how he gives many examples for making your own graphite resistor.

[Thanks Maxime]

Better Temperature Readings Using An Aspirated Thermometer

Unlike regular thermometers that can get incorrect readings because of the sun’s heat, shading, and airflow, aspirated thermometers isolate the temperature sensor from precipitation and the sun, while providing constant air circulation. Take ten 1-wire T2SS boards and combine them with DS18B20s and you’ve got yourself the start of an aspirated thermometer. A foot of PVC pipe, fans, and the above mentioned parts and you’ll have accurate temperature readings in no time.

[Dave] made his to control a natural gas boiler, pumps, and 11 gas-fired unit heaters for a combined output of 5.3 million BTUs per hour – keeping his greenhouse nice and toasty.

Update: Thanks Firetech for pointing out our silly typo.