Outputting Text On A Paper Tape Machine

June 22, 2013 by 24 Comments

thegame

Back before the days of 8 inch floppy disks, storing computer programs was much more primitive than even a stack of punch cards. The earliest general purpose computers used paper tape, a strip of paper with punched holes designating a 0 or a 1. Thankfully for the computer scientists of the day, these paper tapes weren’t created by hand. No, the Friden SP-2 tape punch took care of the duties of punching holes in these tapes. When [Max] rescued one of these tape punch machines from a trash bin, he knew what he needed to do: connect it to an Arduino so he could create his own paper tapes.

[Max] found a veroboard with a bunch of transistors inside the machine that was added by a previous owner. After finding the manual for the machine he connected it to an Arduino, holding each of the eight control pins high to punch the tape, and then holding another pin high to advance the tape. With this, he was able to punch letters instead of binary code into his paper tape.

[Max] also added an Ethernet shield to his Arduino that checks his email. If an email shows up in a special folder, it outputs the subject line to the tape punch machine, giving him an entirely retro ticker tape machine, built with vintage 60s hardware.

There are a pair of videos of [Max]’s tape punch machine in action below, along with a gallery of the glamorous gut shots of this incredible machine.

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Wetlev 2 Water Jet Pack Marginally Less Lethal Than Prior Version

June 22, 2013 by 9 Comments

wetlev2-test-run

You’ve got to admit the thought of tooling around the lake on your own personal water jetpack is a seductive proposition. This is the second summer in which [Toby Gardner] has been trying to work out the kinks on his build. Last year he got out of the water, but the jetpack was pretty hard to control. Over the winter he redesigned the nozzles of the water jets and they seem to be doing quite a bit better.

The fact that the build will be in frequent contact with water makes it a bit harder. They need to have parts that won’t corrode but can stand up to the pressure. Stainless steel was the obvious choice, and for the refinements they were able to get quite a few off the shelf parts to start from. He built a mold for forming the backpack and took it out for a spin. We don’t get a great look at the new version from afar. But watch the videos below and you’ll see last year it tried to drown him, this year it seems to float.

Why is he building rather than buying? Have you seen the price of the original version?

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3D Scanning By Calculating The Focus Of Each Pixel

June 21, 2013 by 42 Comments

calculating-focus-to-generate-depth-map

We understand the concept [Jean] used to create a 3D scan of his face, but the particulars are a bit beyond our own experience. He is not using a dark room and laser line to capture slices which can be reassembled later. Nope, this approach uses pictures taken with several different focal lengths.

The idea is to process the photos using luminance. It looks at a pixel and it’s neighbors, subtracting the luminance and summing the absolute values to estimate how well that pixel is in focus. Apparently if you do this with the entire image, and a set of other images taken from the same vantage point with different focal lengths, you end up with a depth map of pixels.

What we find most interesting about this is the resulting pixels retain their original color values. So after removing the cruft you get a 3D scan that is still in full color.

If you want to learn more about laser-based 3D scanning check out this project.

[Thanks Luca]

Giving A Crank Flashlight A Super Capacitor Overhaul

June 21, 2013 by 25 Comments

crank-flashlight-supercap-overhaul

[Caleb] was given a tiny LED flashlight which has a crank used to charge it. Unfortunately it wasn’t holding a charge, and constant cranking didn’t work very well either. He cracked it open to find a single lithium button cell. Instead of using a drop-in replacement he soldered in his own super capacitor.

The stock device is remarkably simple. It uses a standard DC motor as the generator. It’s connected to the crank using a set of gears, with the two red wires seen above connecting it to the control board. Four diodes make up a bridge rectified and apparently feed directly into the battery. No wonder that cell went kaput!

But this orientation isn’t bad for using capacitors. They can be charged directly and the switch which attaches the LEDs to voltage doesn’t interfere with their operation. The last problem was making room for them in the case. [Caleb] considered a few different approaches, but ended up just heating the plastic enclosure until it could be deformed to make room for the additional parts.

An Arduino Power Inverter

June 21, 2013 by 32 Comments

If you’ve got a few solar panels lying around, or even if you want some 120/230 V AC power from a few 12 Volt batteries, you’ll need a power inverter. Sure, you can drop on down to any big box store and pick one of these up, or you can be like [Michael] and build your own (Danish, translation).

[Michael] found himself in the possession of a few halogen light transformers and decided to make use of them by building a DC to AC power inverter. The inverter is fairly simple – just the transformer, a few MOSFETS, and an ATMega0168 for software control that includes a ‘soft start’ feature that prevents power surges on startup.

The circuit is simple enough to etch at home, although a soldermask and a nice insulated enclosure would probably be ideal for this application.

Building A Synth On A Breadboard

June 21, 2013 by 12 Comments

synth

Building an analog synth is a challenge, but with the [Tymkrs] protosynth, it’s easier than ever. It’s a 25-key keyboard attached to a stack of solderless breadboards to make analog synth prototyping a snap.

Earlier, [Tymkrs] acquired a whole bunch of solderless breadboards and decided to put them to use by making a component-level modular synth. The earlier incarnation tied each key on the keyboard to a few wires behind the breadboard and tied them in to a shift register so they could be read with a Propeller dev board loaded up with a Commodore SID emulator. The new version keeps the very clean through-the-back keyboard connector, but this time the [Tymkrs] are adding a few more components that add a sequencer setup and a rotary encoder.

The eventual goal for this really cool breadboard synth is to explore the world of Moogs, Arps, and other analog synths easily on a breadbaord. The [Tymkrs] have already put together a breadboard-compatible low pass and high pass filter. While there’s still a lot of work to be done to make an analog synth a reality, the [Tymkrs] are off to a great start.

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Hacking A Medion WiFi Streaming Radio Found At Aldi

June 21, 2013 by 20 Comments

hacking-medion-streaming-wifi

On a shopping trip at Aldi [Aaron Christophel] came across this Medion streaming device which connects to your home network via WiFi and works as an Internet radio. He couldn’t resist buying one, and managed to do quite a bit of hacking on the device (translated) once he got it home.

His first order of business was a hardware teardown. An inspection of the board showed what was obviously an unpopulated footprint for a USB mini jack. He added the component, thinking it would allow him to connect it to a computer, but that didn’t work. To investigate the issue further he connected to the device’s serial port using the hard-to-guess credentials root and password. It’s running a Linux kernel and the lsusb command revealed that the USB is enabled as host mode. This mean you can attach mass storage… sweet!

He also did some firmware hacking. Above is the confirmation screen for flashing his altered image file. This resulted in a custom splash screen when it boots up.