Hackaday Links: January 5, 2013

Do not aim laser at remaining eye


Over on the reddits, [CarbonGod] thought he had a slightly overpowered laser pointer. His red laser pointer had a label that said it outputs less than 5 mW. The only problem is it melted black plastic and heated a thermocouple up to 140°F. [CarbonGod] is begging, borrowing, or stealing a power meter from an engineer friend, but until then we’ve got measurements from [The_Sourgrapes]. His lasers put out 105 mW (red), 56 mW (blue), and 53 mW (green).

While <5 mW lasers are fairly safe, these lasers that are labeled as having < 5 mW of output are not. Now if we only knew where to buy these overpowered lasers…

 It’s impossible to find this video in HD


[Zach] created a physical rickroll device. It’s an Arduino and an MP3 shield hooked up to an ultrasonic sensor. When someone walks within six feet of the device, the Arduino starts playing Never Gonna Give You Up. When that person walks away, the song is paused only to start again when something else is detected by the ultrasonic sensor. There’s a hilarious video of [Zach] triggering his physical rickroll device, or you can check it out on the build page.

Hey, you! Write some code!


[William] wrote in to tell us about a project called ReactOS. The goal of the project is to create a free and open source operating system that is binary comparable with Windows XP. Yes, this project has been around for a very long time, but with Microsoft dropping support for XP, the ReactOS team could really use a few devs to get a beta out soon. If you know a bunch of low-level Windows stuff but haven’t ever contributed to an open source project, check out the developer’s wiki.

I’m [Johnny Knoxville] and this is electrostatic discharge


It looks like [Mehdi] is making a few instructional videos for EEs and those tinkering around with electricity. So far he has tutorials for making proper wiring connections, what not to do with ESD, how to take capacitors for granted, and demonstrating how electricity can kill you.

Penitent man shall pass…. Penitent man shall pass…

If gift giving were a contest, [Bradley] would win. His sister’s favorite movie is Indiana Jones and the Last Crusade, so when he needed to wrap a gift (a coffee cup, fittingly), he went all out. All the challenges required to obtain the Holy Grail are present in this present including the breath of God (needs more circular saws), the name of God (why was the letter ‘J’ even in the movie?), and the Leap of Faith (sand included).

Coming up for his sister’s birthday, a face-melting hair dryer.

AM Chiptunes played by a modified antenna analyzer

Believe it or not, this VK5JST aerial analyzer kit is going to rickroll you. [Erich] wanted to see if he could use the device in a different way. His adventure led him to use it to feed different tones to an AM radio, producing the all too familiar [Rick Astley] offering.

There’s a fair bit of math that goes into getting the correct signals to generate a given pitch. But it basically boils down to patching into the hardware early in the RF generation. This way an audio signal can be rolled into the carrier frequency. Since this kit uses a PicAXE microcontroller with available source code it is rather easy to add audio input to tweak what the chip is putting out. But there is also some hardware tinkering to be done. Read more about that at the article linked above, and don’t forget to check out the bottom of that page to hear the final results.

Rickrolling remote control prank

This device is a prank or gag that [Eric Heisler] came up with. It will intercept IR remote control codes and play them back after a bit of a delay. The example he shows in the video (embedded after the break) catches the television power signal from a remote, then sends it again after about thirty seconds. This shuts off the TV and would be extremely annoying if you were unable to find the device. Fortunately (for the victim), [Eric] included a piezo buzzer that Rickrolls after sending each code. Just follow that tune to find the offending hardware.

He chose to use an ATtiny10 microcontroller. It looks like it’s realizing its full potential as the six-pin package use all available I/O to control the IR receiver module, an IR led, and the buzzer. It runs from a coin cell without regulation and the circuit was free-formed on a tiny surface mount breakout board which hosts the microprocessor.

Steam-powered Rickrolling

This is a steam-powered record player; awesome. But wait, that’s not all. Watch the video after the break for about two and a half minutes and you’ll realize that it’s also a Rickroll. No, you’re not getting baited into clicking through to Rick Astley’s music video, the LP that’s playing on the turntable is a copy of “Never Gonna Give You Up”; all kinds of awesome.

This all started with a steam engine machined from a stainless steel bolt and a brass cylinder. It was tested using compressed air before building the boiler. But what’s a steam engine without a purpose? The problem with using a steam engine as a turntable motor is speed control. This is where we move to modern technology, using an Arduino to measure the RPM and adjust the steam engine using a servo motor.

The builder makes a comment that this sounds terrible, but considering it’s steam-powered we think it sounds just fine.

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