Build Your Own 4-channel Logic Analyzer

February 7, 2012 by Mike Szczys 26 Comments

If you’re just getting into hobby electronics chances are there are lots of tools you’d like to get you hands on but can’t yet justify the purchases. Why not build some of the simpler ones? Here’s a great example of a 4-channel logic analyzer that can be your next project and will add to your arsenal for future endeavors.

As you can see, [Vassilis’] creation uses a cellphone-sized LCD screen as the output. It is powered by four rechargeable batteries and driven by an ATmega8 microcontroller. He’s designed the tool without power regulation, relying on the ATmega’s rather wide range of operating voltages, and a few diodes to step down that voltage for the LCD screen.

As you can see in the clip after the break, alligator leads can be used to connect the test circuit to the inputs (don’t forget the ground reference!). Thee buttons at the bottom let you navigate the captured data by panning and zooming. Perhaps the best design feature is the single-sided circuit board which should be quite easy to reproduce at home.

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Circuit Playground – An Electronics Reference App From Adafruit

February 7, 2012 by Mike Nathan 36 Comments

It’s not everyday that we review software around here, but the folks at Adafruit recently put together an iOS app that I figured might be of interest. Their iPad/iPhone compatible application is called “Circuit Playground”, and it includes all sorts of handy electronics reference tools. For the context of this review, it should be noted that I paid for the application myself, and that I have had no communication with the Adafruit team regarding my assessment of the app.

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Printable Wire Stripper Lights Up When You Hit The Conductor

February 3, 2012 by Mike Szczys 57 Comments

Agonize no more over stripping the insulation off of tiny wires like those used in ribbon cables. For years we’ve used razor blades to do this, as the tiniest wires don’t have a slot on our trusty wire strippers. But often we cut all the way though the conductor (or many of the strands) when doing so. [Bjbsquared] came up with this design that will alert you when you’ve hit the conductor.

It uses the two metal razor blades as electrodes in the LED circuit. When anything metal connects the two, the LED will be illuminated. This way you know you’ve cut far enough, and should be able to tug the insulation off of the wire. This image only shows half of the printed unit, a second piece covers up the inner workings, and helps keep stray fingers away from the edges of the blades.

Overkill? We don’t think so, and we hope everyone will agree this is a wonderful design.

[via Reddit and Gizmodo]

3D Print In Wax, Cast In Metal

January 31, 2012 by Kevin Dady 39 Comments

What does dry ice, ethonal, wax beads, and a blender have in common? It was the first attempts at making media for this wax 3D printer that [Andreas] has been building up. Wanting to produce 3D printed objects out of metal, and finding that direct metal laser sintering machines were still out of reach of reason, he set out to find a different way.

After trying a few different methods of making the powdered wax himself, he decided that it was much more time effective to just buy the stuff. Using the commercially available powered wax mixed with activated carbon, and a custom printer, the wax is blasted with a moderately high powered laser. More wax powder is applied over the freshly sintered layer, and the 3d part is built upwards. Once he has the part in wax, he can then make a mold of it and cast metal using the Lost Wax Casting method.

While the quality is not perfect, and you still need a roughly 2500$ laser setup (which was borrowed from his school) its surely a step into the future.

Join us after the break for a quick video.

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A SOPA We Still Can’t Get Behind

January 30, 2012 by Brian Benchoff 15 Comments

[Brad] had an extremely productive January 18th. Considering how many websites went dark to protest SOPA, we can’t blame him. While considering what he could get done if popular Internet time sinks went dark on command, [Brad] thought of the Stop Online Productivity Avoidance box. This build will redirect all traffic to sites like reddit, hacker news, and (gasp!) hack a day to a simple web page that asks the eternal question, “shouldn’t you be working right now?”

The box has two modes: in SOPA mode, the whole Internet is at [Brad]’s fingertips. In NOPA mode, an Arduino communicates with a Python script running on the router to pull up an Internet blacklist. A simple button would be too easy to override, so there’s a ‘nuclear mode’ that shuts off these time sinks for one hour. The only way around the blacklist is to restart the router, a process that takes 15 minutes and will kill the entire Internet for the duration. Not something you’d like to do if you’re slightly bored.

All the code for the SOPA box is up on github and you can check out [Brad]’s demo of the SOPA box after the break.

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Powering An Ultrasonic Transducer

January 30, 2012 by Kevin Dady 25 Comments

[Lindsay] has a wonderful writeup about a new toy in the shop, an ultrasonic transducer. The 28kHz, 70W bolt-clamped Langevin transducer by itself is not much use, you need a power supply, a horn to focus the energy, and a way to tune it. [Lindsay] starts off by showing how to find out the resonant frequency of the transducer, designing and building a high voltage high frequency AC power supply, and how to design a horn.

Not missing the meaning of DIY [Lindsay] casts and machines a horn for the transducer with a high level of precision as this will also tune the horn to the correct frequency. Once some brackets are machined the whole setup is put through some fun experiments in water and lemonaide, but the real purpose is to drill fine holes in glass for his home made Panaplex displays.

Join us after the break for a short video.

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Converting A Mill To CNC

January 24, 2012 by Brian Benchoff 16 Comments

For most of the past year, [Joel] has been working on converting a manual mill to a CNC mill with the addition of a computer, brackets and stepper motors. He’s put an amazing amount of effort into his project, and the result is awesome and much less expensive than buying and shipping an old Bridgeport mill.

The project started with this mill from Grizzly. It’s a step above the small ‘hobby mills,’ but still very affordable at $1200 shipped to [Joel]’s driveway. The work began by fabricating an enclosure for the PC and motor drivers out of an electrical panel box. The controller box includes a touch screen, keyboard and computer running Mach3 CNC software. The computer connects to a breakout board with a trio of motor drivers providing power for the stepper motors on each axis.

After a few months (good things take time), [Joel] was ready to attach the stepper motors to the axes of the mill. He’s just put up a few videos of milling copper-clad board for PCBs and surface machining ABS, viewable after the break. For a total investment that is less than finding, buying, and repairing an old industrial mill, we’ll call [Joel]’s project a success.

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