Sinclair ZX Spectrum +2A Slims Down

May 21, 2014 by 37 Comments

sinclair

[Carl] got his hands on a dead Sinclair ZX Spectrum +2A. He decided he wasn’t just going to fix it, he was going to improve it! The ZX Spectrum Compact is literally a “sawn-off” Spectrum +2A. [Carl’s] inspiration came from a similar mod at the Old Machinery blog.

Amstrad seems to have had a habit of bolting on additions to their products. In the case of the Spectrum +2A, it was a tape drive. Tapes weren’t a great storage method in the 80’s, and today they’re downright annoying. [Carl] didn’t need the tape interface, as he’s using a DiVide ATA interface.

The modification is rather straight forward. [Carl] broke out the hacksaw and cut the right end cap away from the tape drive. He then cut the entire tape drive away. The motherboard wasn’t safe from the saw treatment either, as the printer interface was cut off. Thankfully there were no components on the printer interface. Apparently [Carl] didn’t short any traces as he went to town with his saw.

With the motherboard modified to fit the abbreviated case, [Carl] was ready to begin reconstruction. He glued the cap onto the sawn-off case with Grip Fill glue, which also served to fill any gaps. Some sanding, priming, and painting later, The ZX Spectrum Compact was finished. This isn’t a perfect mod, as the gap is still slightly visible under the paint – but it’s good enough for [Carl]. Hey, it’s good enough for us, too – we can’t all be [Ben Heck]!

 

Candle Powered Fan Keeps You Cool Using A Thermoelectric Generator

May 21, 2014 by 62 Comments

This is a great example of using a thermoelectric generator for a project. [Joohansson] made both a functional, and aesthetically beautiful fan using components from a computer.

Thermoelectric generators (TEGs for high temperatures, and cheaper TECs for lower temperatures) are also called peltier elements, which look like small square pieces of ceramic with two wires sticking out of them. If you supply power to it, one side will become hot, and the other cold. The TECs [Joohansson] is using want a temperature difference of 68C between either sides. They are typically used for cooling electronics and even some of those cheap mini-fridges will make use of one with a giant heat sink on the hot side.

In addition, they can be used as an electric generator, thanks to the seebeck effect. If you can create a temperature differential between the two sides, you can generate electricity. Using a CPU heatsink, cooler, and fan, [Joohansson] was able to power a small DC fan using only a candle. It’s a brilliant demonstration of the seebeck effect.

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A Levered Light Switch Even Fido Can Operate

May 21, 2014 by 35 Comments

Dog Light

We love hacks that make a difference in people’s lives. Service dogs can make a huge difference in a physically disabled person’s life, and while they can do a lot of things, dogs aren’t the greatest at flipping light switches. So a team of industrial design students from Ghent, Belgium decided to try finding a solution.

Their case study was for a young woman named [Heleen Bartsoen]. She has a very smart white golden retriever named [Gyproc] who is very good at picking up commands, and is a very careful and cautious service dog. She has an IKEA lamp with a foot switch that neither she or her dog can press.

The team quickly got to work and decided to design a lever to give the dog (or Heleen!) some mechanical advantage to actuate the switch. Having access to a laser cutter, they designed the lever to be cut out of plywood for easy assembly. It pivots around a wooden dowel, and they’ve filled a compartment of the base with cement to keep it stationary when being used.

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Capacitive Sensing And Old IBM Keyboards

May 20, 2014 by 12 Comments

The pen is mightier than the sword, but the IBM Model M keyboard, properly applied, can knock teeth in. There are a few more IBM keyboards even better suited to blunt force trauma – the extremely vintage beam spring keyboards made for terminals and desktop publishers. Being so very old, there’s no easy way to connect these keyboards to a modern system, so when [xwhatsit] wanted to make his work, he needed to build his own controller.

The beam spring keyboards use capacitive switches, and with 122 keys, the usual method of reading capacitance – putting a capacitor in an oscillator – would be far too slow to be of any use in a keyboard. There is another method of reading capacitance: measuring the current going through the capacitive switch. This can easily be accomplished with an LM339 comparator.

[xwhatsit]’s keyboard controller uses this capacitive sensing circuit to read the four rows of keys, with a few shift registers taking care of the columns. An ATMega32u2 is the brains of the outfit, running LUFA to translate the key presses to USB.

If you’re lucky enough to have one of these ancient keyboards, [xwhatsit] is selling a few over on the usual mechanical keyboard forums. There’s also a controller for the Model F keyboard using the same basic circuit. If you need one just drop him a line or grab the gerbers and roll your own.

Barobot Serves Cocktails While Using Open Design The Right Way

May 20, 2014 by 30 Comments

barobot-mechanical-bartender

Oh for the day when we can stop repeatedly looking up our favorite drink recipes on Wikipedia. Those may be just around the corner and you’ll have your choice of single-click delivery or toiling away in the workshop for a scratch build. That’s because Barobot is satisfying both the consumer market and our thirst for open hardware goodness. They’re running a Kickstarter but to our delight, the software and mechanical design files are already posted. Before you dig into the design files there’s a really good look at the constituent parts in the assembly manual (PDF) — that’s a lot of pieces! — and a tiny bit on the tech-stuff page.

This remind us of the Drinkmo we saw earlier in the year. That one cames complete with the high-pitched whine of stepper motors. We didn’t get to hear Barobot’s ambient noise in the promo vid after the break. But one place this desing really shines is a swiveling caddy that allows for a double-row of bottles in a similar footprint. One thing we’d be interesting in finding out is the cleaning procedure. If anyone know what goes into cleaning something like this let us know in the comments.

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Neo Geo Gets Line Doubled

May 20, 2014 by 26 Comments

NeoGeoScan

We love old video games, but we hate the way analog interlaced video looks on our new LCD monitors. [Michael] feels the same way, so he’s created NeoVGA, A Neo Geo Line Doubler in VHDL. Neo Geo, like many classic consoles, didn’t use the full resolution of an analog TV. In NTSC mode, it ran at 320×224 pixels. PAL users got an extra 32 vertical pixels for 320×256 pixels. The system ran with an approximately 15kHz horizontal sync and ~60Hz vertical sync.

This is not exactly a VGA compatible signal, so it would be relegated to composite or S-Video capable displays. The signals looked pretty good on a CRT, but on an LCD, they tend to look crummy. Modern LCDs don’t natively handle interlaced and/or low resolution input signals. The TV’s controller performs the magic of buffering, interpolating, and transforming the input signal to be compatible with the LCD panel. As [Michael] explains, most of these algorithms are optimized for TV video signals with lots of motion. They perform poorly on static high contrast images such as the background of a fighting game. TV controllers also add lag to the signal chain. Not much of a problem when watching movies, but it’s a big problem when you’re trying to pull off that triple hit combo.

Click past the break for more on [Michael’s] creation.

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Sealed-System Bucket Loader Cleans Messes In Dangerous Places

May 20, 2014 by 23 Comments

[youtube=https://www.youtube.com/watch?v=XjHJ71SVop4&w=580]

 

Cleaning up after a disaster is hard and dangerous. But the ROEBL project is trying to make it substantially safer by removing the human operator from harm’s way. The Remote Operated Electric Bucket Loader had a big double-fenced, cement barrier play area set up at Maker Faire and [Justin Gray] walked us through the project which concluded with a demonstration of the hardware.

For now the operator does need to be on site to see what the loader is doing, but a first-person video setup is planned for the future. Still, removing the operator from the jarring experience of riding inside is an improvement. And the sealed nature of the electric and hydraulic systems mean that it can operate in areas inundated with liquids like water or oil.

The video above has a 90 second demonstration at the end (while we all laugh like children at what really was a giddy display of power being thrown about by a handheld controller). The ROEBL website has a gallery where you can see the conversion process that started with a standard diesel machine.