Hack a Day Classifieds


Announcing Hack a Day Classifieds! Buy, sell, trade your tools and junk with other Hack a Day readers.

Quite often, we get emails or comments with people asking “do you want this piece of junk?” or “Would you sell that thing?”. We usually just push them off on craigslist, but we realize that it can be hard to find our specific flavor of stuff in craigslist. Who posts a half smashed tube radio on there?

Our answer is to give you guys the Hack a Day Classifieds. We know it isn’t perfect, but we wanted to supply this service to hackers. Feel free to post what you’ve got. Think of it like a little mini craigslist, just for us. It should be fully functional and ready to go, but who knows what issues we’ll see when you all start going there. Please be patient and understanding with us.

Five Free Evalbots

If you’re a member of a hackerspace and you’ve been hoping and wishing for an evalbot to tear apart with your bare hands, you’re in luck! [Dave Bullock] is giving out five evalbots to five lucky hackers chosen at random. We thought that the $125.00 deal we saw the other day was good but this is right outta town!

The draw is on Black Friday, so you’ve got a few days to submit your details. We’ve only had a few posts about the evalbot to-date covering the initial examination of the hardware and a USB power modification. We’re interested in seeing where people take this, and we’d love to follow how each of these free ‘bots turns out. For those already working on an evalbot, keep it up and take lots of pictures!

[Photo credit: Dave Bullock from eecue]

Build your own SOIC progamming clip

[Pyra] was looking for a way to reprogram some ATtiny13 microcontrollers in a SOIC package. He’s re-engineering some consumer electronics so adding an ISP header to the design isn’t an option. He had been soldering wires to the legs of every chip but this is quite tedious. What he needs is an adapter that can make physical contact with the legs just long enough to program new firmware. After looking around he discovered that a PCI socket can be used as a progamming clip (translated). It shares the same pitch as a standard SOIC package but is not wide enough for the chip. He cut out 4 rows of the socket and the section of motherboard it was soldered to. Then he made a cut down the middle of the plastic and bent the two sections apart. The image above illustrates this, but not shown are the eight wires that he later added to connect to the device.

We wonder if this can be adapted to program SOIC parts without removing them from a circuit board. That would be a handy tool for finishing up the LED lightbulb hack.

Well-balanced flight simulator

Here’s a flight simulator which uses concepts simple enough for anyone to build. As you pilot your virtual craft, the cockpit you’re sitting in moves as well. But unlike some of the more extreme simulator builds we’ve seen, this uses basic materials and simple concepts to provide that motion. Its center of gravity is balanced on a base frame. The joystick slides as you move the nose of the craft up and down, shifting the center of gravity causing the cockpit to tilt as well. The pilot sees the simulated flight through a wearable display. There is a stationary reference in front of him which allows the system to measure head movements, panning and tilting the virtual display to match. Check out the overview video after the break, or click through to the page linked above and watch all 22 episodes of the video build log.

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Global Village Construction Set

The Global Village Construction Set is an open hardware initiative aimed at sharing tool-building knowledge. They believe that to build civilization you need forty basic tools, eight of which they’ve already prototyped and made available on their wiki. Included in these is a tractor which reminds us of a beefy bobcat. It has a soil pulverizing attachment which can be used to break down soil and feed it to their soil brick compressor. That machine spits out compressed dirt bricks which are used as building materials. They’re stacked on concrete footings and then limewashed to protect the un-baked bricks from water erosion. Does this remind anyone else of real-life Minecraft?

Above you can see a group of Open Source Ecology developers showing off bricks in front of the machine that made them, with the tractor/soil pulverizer to the right. Take a look at the videos about the construction set and brickmaking after the break. And learn more by perusing their weblog.

If you think an apocalypse is on the way you might want to buddy-up with these folks. They seem to know what they’re doing.

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Electromechanical computer built from relays

This is Zusie, a computer built out of electromechanical relays. [Fredrik Andersson] picked up a lot of about 100 telephone exchange circuit boards, each with about 16 relays on them. After getting to know a heat gun really well he ended up with 1500 working relays with which to play. The machine runs slowly, it iss noisy, but it definitely works. After the break you can see it running and assembly code program that he wrote.

The instruction set is based on boards running microcode. These store the operational commands for each instruction the processor has available to it and they run in parallel with the rest of the operations.

We’re always surprised to see that these home-built processors work. Mostly because of the complexity involved in assembling them. How hard is it to find a shorting connection or a malfunctioning relay? Those problems aren’t limited to this application either, what do you do if a transistor-logic CPU has a malfunctioning chip?

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