Apple ][ Converted Into USB Keyboard

June 6, 2011 by Brian Benchoff 15 Comments

Sometimes it’s apparent that there is no practical use for something featured on Hack a Day, but we don’t know if [Andrew Filer]’s Apple ][ USB keyboard qualifies for this.

After reading through the very thorough documentation available in electronic and dead tree formats, [Andrew] decided that Apple ][ would make a great USB keyboard. Unlike modern keyboards, vintage computers like the TRS-80, Commodore 64, and the Apple ][ return the 7-bit ASCII value of the key instead of a scan code. The ASCII codes generated by the keyboard were sent through a Teensyduino running [Andrew]’s keyduino sketch.

Modern PS/2 keyboards use MAKE and BREAK scan codes sent from a microcontroller that reads the keyboard matrix. For example the MAKE code for the letter ‘A’ is 1C, while the BREAK code is F0 1C. There is a reason for this design, but for the DIYer, interfacing a keyboard becomes a challenge without a separate microcontroller. We’re thinking [Andrew]’s keyduino could be a great way to put a keyboard in a project, but we’re not about to tear up our Apples and C64s to get a keyboard.

DIY Digital Bench Power Supply

June 6, 2011 by Brian Benchoff 30 Comments

[Guido Socher] built himself a great little bench power supply that’s able to put out 30 Volts at 2 Amps.

Instead of taking the easy way out by putting a few taps on an ATX power supply, this project was built around a generic 24 Volt laptop power brick. An ATmega8 generates a PWM signal that is sent though a low-pass filter, allowing everything to be very precisely controlled. This DC signal is then sent through a BD245 power transistor to bring everything up to the desired output. [Guido Socher] included a USB port for computer control of everything, and the final project is something we’d be happy to have on our bench.

We’ve seen a few computer power supplies converted into a bench power source, but we’re impressed with [Guido Socher]’s build log. It’s not often we see a hack that goes over the theory of operation, and the end product is very nice (and functional) too.

Build Your Own Panoramic Pinhole Camera

June 4, 2011 by Mike Nathan 3 Comments

panoramic_pinhole_cam

While it seems that the digital camera is king, some people still love shooting with good old 35mm film – [Costas Kaounas], a high school teacher and photographer certainly does. He recently published plans for a great-looking 35mm pinhole camera over at DIY photography that we thought you might enjoy.

[Costas] put together a set of simple hand-drawn plans for the camera, that you can easily replicate with a bit of free time. The camera is built mostly from card stock, both in 1mm and 3mm flavors, also incorporating popsicle sticks and an aluminum can. The popsicle sticks are used to create a manual shutter for the camera, while the pop can is used to form the pinhole aperture.

It’s a pretty simple hack as you can see, with nary an electronic part to be found. It will take you a bit of time to construct however, since you’ll need to let the glue dry between certain steps.

Love it or leave it, you’ve got to admit that the panoramic shots it takes are pretty nice!

If we’ve piqued your interest in pinhole cameras, be sure to check out this Lego pinhole camera as well as this beer can pinhole camera.

[via Lifehacker]

[Dino] Celebrates The 131st Anniversary Of The Photophone

June 3, 2011 by Mike Nathan 24 Comments

photophone_demonstration

[Dino Segovis] wrote in to share yet another installment of his Hack a Week series, though this one is quite timely.

It was 131 years ago today that [Alexander Graham Bell] unveiled the Photophone to the world. A precursor to fiber optic technology, [Bell’s] incredibly important invention can be easily replicated in your garage, as [Dino] shows us.

The original Photophone was constructed using a megaphone and crystalline selenium cells at the focal point of the receiver, however this version can be made with easy to obtain parts. [Dino] rigged his laptop up to a speaker on which he mounted a mirror, before setting it out in the sun. The vibrations of the mirror modulate the sunlight, reflecting it onto a solar cell positioned at the end of a long, black PVC tube. The solar cell’s leads are fed into an amplifier followed by a speaker, which broadcasts the audio.

The demonstration goes off without a hitch, and while some might be underwhelmed by the technolgy, imagine how incredible it would have looked 131 years ago!

Portable SID Plays Chiptunes

June 3, 2011 by Brian Benchoff 19 Comments

[Markus] on the DangerousPrototypes forum came up with a great little SID player.

The SID was (is?) the awesome sound generation chip inside the Commodore 64, and along with Game Boys and NESs laid the foundation for the chiptune scene. We’re happy to finally see a small SID player that doesn’t resort to SID emulation or a relatively huge MIDIbox.

The SID player itself is a shield on a CUI32 PIC dev board. The PIC32 emulates the 6510 and 6526 CPU and CIA chips found in the Commodore 64. A small USB memory stick stores the High Voltage SID Collection and the file system is navigated with an OLED screen. [Markus] says that the player draws 370 mA, so he runs it off a small wall wart. Still, we’re wondering if it’s possible to run this off of an SD card with a SwinSID so power draw can be reduced and a fully portable SID player can be realized.

We’ve got a touch of nostalgia for chiptune and demoscene music right now, so we’re going to listen to some ~~[Nelly Furtado]~~ [Janne Suni] right now, but you can check out the video demo [Markus] posted after the break.
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Quadruped Military Vehicles From Back In The Day

May 28, 2011 by Mike Nathan 14 Comments

While Boston Dynamics’ Big Dog is pretty impressive, check out this video of the US Army’s first attempt at a quadruped vehicle. Created in the early 1960s with the help of GE, this Army experiment was the first successful attempt of replicating a four-legged animal with a mechanical machine.

This “Walking Truck” was driven by a single operator who moved each of the vehicle’s legs using force-feedback hydraulic levers. Choreographing the machine’s movement was quite complicated, and during testing the Army found that the operator needed a mental break after only 15 minutes of use. As you can see in the video, the vehicle flexes some serious muscle. It kicks a Jeep out of its way with little effort, but it is still able to gently step on a light bulb without breaking it, due to the level of tactile feedback received by the operator.

If it weren’t for government budget cuts, we could be living out [George Lucas’] dream of AT-AT based combat right this minute!

[via Gizmodo]

Minimalistic 555 Adding Machine

May 27, 2011 by Nick Schulze 6 Comments

How many 555 timers does it take to add up two 10 digit numbers? [Alan’s] 555 Adding Machine does it with 102 of them, he designed the machine as an extreme entry to the 555 contest and the original plan was to make it even more complicated. This machine uses the 555’s to implement a nine decade accumulator and multiplexer, all inputs are managed by an old school dial from a rotary phone which apparently provide nicely timed outputs. Addition and subtraction are achieved using 9s compliment arithmetic which he discusses in the video after the break, for anyone who wants to brush up on 9s compliment or 555 theory.

Alan’s website has some nice pictures (We’re particularly impressed by all that minimalistic soldering) including schematics, and a very nice 33 minute video in which he discusses in detail how the machine works and even offers some history on the Pascaline, which is mechanical calculator that works on similar principles.

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