Cellphone Controlled Retro-radio Stores And Plays Your Digital Library

August 24, 2011 by Mike Szczys 6 Comments

[Autuin] was worried about having desirable electronics stolen while on the road with his band. He didn’t want to take a laptop along on tour, but he didn’t want to be without his music either. To solve this problem, he built a music player inside of a cheap-looking radio. His write-up covers two different portable MP3 solutions, but it’s the second rendition that catches our attention.

After hollowing out the old radio he filled the void with an Asus WL-HDD 2.5. That hardware is meant to be an easy way to add network storage; it houses a laptop hard drive and has WiFi and Ethernet connectivity. But it also has one USB port, and can be hacked to add a second. [Autuin] did just that, using the two USB connections to add a Bluetooth dongle and a USB sound card. Music is synced with the hard drive via some cat-5 cable that’s hidden in the battery compartment of the vintage box. The NAS runs Linux, and the audio playback software is controlled though a Mobile Java application running on a somewhat broken cellphone. That’s an idea that might find its way into our next project.

Water-powered Multi-channel Audio

August 24, 2011 by Mike Szczys 8 Comments

[Niklas Roy] is rolling out some water-powered music for Berlin’s Museum night. It seems that this water-wheel is attached to the side of the Museum. It’s got a stream flowing past it and the wheel is constantly turning. The thing is, that work isn’t being used for anything. Now we’ve already seen [Niklas] making electricity from moving water, but that’s far from what he had in mind this time around. Instead he’s driving a multitude of music boxes with the motion transferred from the water.

He teamed up with another artist named [La belle Imira] to build and connect a series of pulleys to the waterwheel. The video after the break shows the rope system being strung throughout the grounds of the museum. After passing around the output drum of the water wheel, the rope snakes through each pulley. Many of the pulleys have the mechanism from a music box attached to their axles, so whenever the water is flowing, music plays. They don’t all play the same tune, so you get a variety of selections as you walk around. We could swear that one of them is playing ‘My Way’.

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High Voltage: Build Your Own 84 KV Lightning Stick

August 24, 2011 by Mike Szczys 6 Comments

There’s a proverb that says ‘Speak softly and carry a big stick’. Now that stick can come in a high-voltage form factor. The device above, which reminds us of a side-handled baton with a coke can stuck on the end, is a portable Van de Graaff generator.

Although debated in the comments, the creator of this hack claims you can shock someone with 84 kV of electricity using the device. Of course as a weapon it’s lacking since we’re talking about static electricity; the voltage can be through the roof but the current is extremely low. Despite that, there are some fun things you can do with them. The video after the break show it throwing off sparks with the lights dimmed. [Yardleydobon] also includes a few other tricks at the end of his tutorial. He makes a set of Franklin Bells using two more soda cans with the aluminum tab from one suspended in between them. As he charges it up, the tab dances back and forth, ringing the ‘bells’ it runs into. Once they are charged, the ringing can be restarted by discharging just one of the cans.

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Home Tanning Lamps Become Organ Donors For A PCB Exposure Bed

August 23, 2011 by Mike Szczys 4 Comments

Some projects benefit greatly from the parts a builder is able to find. Take this UV exposure bed for photo-resist copper clad boards (translated). It looks like a commercial product, but was actually built by [TabascoEye] and his fellow hackers.

The main sources for parts were a flatbed scanner (which acts as the case) and two self-tanning lamps that use UVA flourescent bulbs. By sheer luck the bulbs and their reflectors are exactly the right size to fit into the top and bottom cavities of the scanner. The control hardware centers around an ATtiny2313 micorocontroller, which takes input from a clickable rotary encoder, and displays exposure information on a character LCD. The finished product deserves a place right next to other professional-looking exposure boxes that we’ve looked at.

Winterizing: Keeping The Drafts Out Of Double-hung Windows

August 23, 2011 by Mike Szczys 22 Comments

[Rumplestiltskin] has had work done on his double-hung windows to help prevent drafts and keep them in good working order. But there are still a few that rattle, and let in the cold of winter. Not this year; he’s added a small feature to the jamb that will keep out the cold weather.

A pair of jointing blocks were added to each window. The small block seen above is attached to the window jam with a couple of all-purpose screws, and hosts a machine screw which points toward the window frame. Since there is weather stripping between the two window frames, and between the frame and the outer jamb, tightening this screw will snug the frames up to close any small gaps. This has the unintended consequence of prohibiting the window from being opened (unless you don’t mind scraping the paint as the machine screw slides across the wood). But if only used in the winter months this is a viable solution.

Can A Dippy Bird Be Used As A Temperature Sensor?

August 23, 2011 by Mike Szczys 9 Comments

Dippy birds are the toys that teeter-totter back and forth as the beak of bird-shaped body dips into a container of water. The felt covering the beak and head picks up water and, through evaporation, cools that end of the glass tubing. The temperature changes cause the dichloromethane to either boil off, or condense, shifting the weight of the liquid thereby pivoting the glass body.

The real question is, does the temperature of the water cause the toy to move differently, and can that be measured to calculate the temperature of the water? [Craig] put that query to the test, by designing an apparatus to measure the motion of a Dippy Bird. A photointerruptor was used to measure the motion of the body, causing an interrupt each time the tail of the bird passes in between the sensor and the emitter. For control data a DS1820 temperature sensor was positioned near the felt on the head of the bird, and a relative humidity sensor captured readings at the same time. Data from the three inputs was collected over a two-day period. Although not a precise measurement, the motion of the bird did trend in the same ways that were recorded by the temperature and relative humidity sensors.

Setting It Straight About Science Fair Solar Energy Breakthrough

August 22, 2011 by Mike Szczys 58 Comments

There’s been a lot of stories about arranging solar panels to mimic leaves on a tree, thereby boosting their efficiency. But before reading that story you might want to check out this blog post correcting some flaws in that breakthrough (page is down, here’s a cached version).

Before we go any further, we’d like to point out that the original work was done by a seventh grader. He looked at leaves on trees and postulated that the Fibonacci sequence can be found in the layout of leaves, and that by laying out solar cells in the same way you can capture more sunlight. Comments can get negative fast around here, so remember that trashing his work may discourage other kids from participating in science fair events.

Anyway, long story short: there were some issues with original assumptions, and about what was actually being measured during testing. The article linked at the top covers the fact that the cells were not measured under load, and that simple calculations can show why the tree-mimicking-cell-placement can be proven sub-optimal to 45 degree, south-facing solar farms.

[Thanks Jeffery and Steve for the original article and Brian for the follow-up article and cached link]