Radar gun teardown

[Jeri Ellsworth] is at it again, this time she takes apart a hot wheels speed gun and in the process she does a good job of  explaining how radar can be used to measure speed.  She also demonstrates a way to determine if an object is approaching or receding from the radar gun.

The Doppler shift is one way to … Read the rest

“Strong enough to lift a person, yet gentle enough to embrace a child.”

Tentacles have inspired fear and respect in humans long before anime came into the scene. Sailors shivered in their timbers at the thought of the great Kraken, or that octopus from 20,000 Leagues Under the Sea. It’s no surprise to know that humans have been trying to harness this fear and respect in technological form since the mid-20th century … Read the rest

Wiffletree: a mechanical digital to analog converter

This isn’t a hack. But it is a decidedly interesting piece of mechanical technology. The Whiffletree shown above is a way to turn binary data into a mechanical analog value. [Bill Hammack] explains how this assembly is used in a typewriter and how a whiffletree can convert binary data to a set of analog outputs.

These linkages are what … Read the rest

Audio controlled party lights

[Thibault Brevet] wanted his own party lighting that pulsed and faded along with the tunes. He ended up building a system based on an Arduino and a PC running Processing. The output from a mixing board is fed into a PC and measured by the Processing script. From there, the calculated light levels are sent to the Arduino to address … Read the rest

RFID spoofer with code and instructions

Here’s a field-programmable RFID spoofer developed by [Doug Jackson]. He was inspired by the spoofers we looked at near the end of September that didn’t have source code available. With the idea seeded in his mind he figured he could develop his own version, and then decided to share the build details with the rest of us.

The tags … Read the rest

Hackaday links: November 28, 2010

The Clock Clock

This digital display is made from several analog clocks with thick hands. Together they make something of a 7-segment display, which can be used to display the time. It reminds us of the “Shared Time” installation we covered previously. [Thanks Drum365 via Anonimiss Files]

Quickly desolder lots of parts

[Rhys Goodwin] is grabbing parts from … Read the rest