Meter Clock With Pleasing Design Considerations

[AndyO] embraced his inner geek by building this meter clock. It exhibits a lot of features that you’d want to see in a home-built timepiece, include over-complexity, abundant features, and RGB LEDs. We’re fascinated by the design he put into this. For instance, the two indicator LEDs on the clock face are not poking through the surface, but use brass tubes as light pipes. Also, the three buttons on the top are almost indistinguishable, and have an RGB back light that places a halo around each. The case itself was built by first making a form, then laminating thin sheets of wood (a difficult task due to the tight curves). The needles themselves are not actually meters, like the clock the inspired the build, but are attached to servo motors. This all comes together into a fascinating build, and a great writeup.

[Thanks Graham]

Knitting Machine Hack By Keypad Emulation

[Travis Goodspeed] and Hackaday alum [Fabienne Serriere] joined forces to develop an alternative interface for a knitting machine. They’re working with the Brother KH-930E machine. We saw [Becky Stern] use the same model by manipulating data on an emulated floppy drive for the device. [Travis] and [Fabienne] went a different route, and are emulating the keypad using an Arduino and a set of transistors.

They started by reverse engineering the keypad matrix using a continuity tester. Once they worked out the column and row layout they connected each to an NPN transistor. The Arduino sketch simulates button presses to set knitting bits for each row, with just one reset button for user input. This can be used to send data from a PC, or as a standalone system. Either way, it’s not only a great way to add functionality to the kitting machine, but a good example of how to interface with the keypad on just about any device.

Star Trek Inspired Pocket Doors

Do you have enough confidence in your hacking abilities to build a project into the walls of your home? [Marc] used his skills to build an air-powered sliding door for his bedroom. It is similar to the sliding door you’d find on the Enterprise, two sections that slide nicely into the wall to let you pass. Although the picture above shows the internals, he followed through and ended up with a fully finished room that looks fantastic. A compressor in the attic provides the pressure necessary to move the door sections. It is automated, but uses a button press or keypad combination to run instead of detecting motion. Of course, since he’s using a PIC microcontroller to drive the system there’s always room for future changes. Check out how great the finished look is in the video after the break.

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Hot Resistors Used For Color-changing Clock Face

[Sprite_TM] built a full clock display using thermochromic paint. This picks up where he left off with his paint-based 7-segment display prototype. He never really saw that design through to a finished project, but he recently came across the leftover paint and decided to do something with it. Instead of making thin traces on a PCB he’s heating up resistors mounted on protoboard. Each resistor has been coated with the black/light grey paint after getting a rough sanding on the tops of the packages. Run around 500mW through a segment and they heat up enough to change the paint to light grey. Once shut off, the segments gradually fade over the next 60 seconds.

Breathing Motion Powered USB Charger

When your batteries run low you can use your body to recharge them. This contraption generates power from chest expansion while breathing. [Jmengel] used some gears from old optical drives to boost the RPM generated by a belt around your torso that he calls a thorax expansion coupler. When you breath in, that belt pulls on a plate that spins the gears, ultimately rotating a small motor. The AC current generated by that motor is run through a rectifier and a boost converter, then fed to a charging circuit.

Does it work? Not really, as this only outputs around 50 mW. But we like the twinge of Dune nostalgia we get looking at it. Wouldn’t this be a perfect addition to a stillsuit?

Composite Video With MSP430 Chip

[NatureTM] used part of the Thanksgiving holiday to get composite video output working with an MSP430 microcontroller. He’s using one of the chips that came with the TI Launchpad, which is a big hardware limitation because of the relatively small code memory and RAM. The chip displays one still image at a resolution of 192×40 pixels. Still, this is a great way to learn about composite video signals, as a lot of other projects use a TVout library to save you the headaches. All you’ll need is a TI Launchpad, a 16 MHz crystal oscillator, two resistors, and an RCA jack. Dig through the code and see what a great job [NatureTM] did of offloading as much work onto the chip’s peripherals as possible.

Nerf Gun Converted To CO2 Powered Semi-automatic

[Philysteak527] modified a Nerf rifle, making it semi-automatic thanks to the powers of compressed air. This is not a simple change to make, and rests on his ability to design and manufacture a bolt-action that fits in the gun, works with the Nerf ammo, and uses a CO2 canister and solenoid valve for the firing action. Knowing that, it’s not surprising to find that he’s an engineering student at Stony Brook University. He started with some POM, or polyoxymethylene plastic sold under the brand name Delrin, and used a CNC lathe to machine the parts for the bolt. Add in some brass fittings, a solenoid, tubing, and the electronics and you’re in business.

We’ve embedded the test footage after the break. Looks like the new internals allow a rather fast firing rate (maybe 2-3 shots per second?) and achieve a distance between seventy and one hundred feet.

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