Building A Pocket Sized Arduino Oscilloscope

September 21, 2018 by 10 Comments

There’s little question that an oscilloscope is pretty much a must-have piece of equipment for the electronics hacker. It’s a critical piece of gear for reverse engineering devices and protocols, and luckily for us they’re as cheap as they’ve ever been. Even a fairly feature rich four channel scope such as the Rigol DS1054Z only costs about as much as a mid-range smartphone. But if that’s still a little too rich for your taste, and you’re willing to skimp on the features a bit, you can get a functional digital oscilloscope for little more than pocket change.

While there are a number of very cheap pocket digital storage oscilloscopes (DSOs) on the market, [Peter Balch] decided he’d rather spin up his own version using off-the-shelf components. Not only was it an excuse to deep dive on some interesting engineering challenges, but it ended up bringing the price even lower than turn-key models. Consisting of little more than an Arduino Nano and a OLED display, the cost comes out to less than $10 USD for a decent DSO that’s about the size of a matchbox.

But not a great one. [Peter] is very upfront about the limitations of this DIY pocket scope: it can’t hit very high sample rates, and the display isn’t really big enough to convey anything more than the basics. But if you’re doing some quick and dirty diagnostics in the field, that might be all you need. Especially since there’s a good chance you can build the thing out of parts from the junk bin.

Even if you’re not looking to build your own version of the Arduino-powered scope [Peter] describes, his write-up is still full of fascinating details and theory. He explains how his software approach is to disable all interrupts, and put the microcontroller into a tight polling loop to read data from the ADC as quickly as possible. It took some experimentation to find the proper prescaler value for the Atmega’s 16MHz clock, but in the end found he could get a usable (if somewhat noisy) output with a 1uS sample rate.

Unfortunately, the Arduino’s ADC leaves something to be desired in terms of input range. But with the addition of an LM358 dual op-amp, the Arduino scope gains some amplification so it can pick up signals down into the mV range. For completion’s sake, [Peter] included some useful features in the device’s firmware, such as a frequency counter, square wave signal source, and even a voltmeter. With the addition of a 3D printed case, this little gadget could be very handy to have in your mobile tool kit.

If you’d rather go the commercial route, Hackaday’s very own [Jenny List] has been reviewing a number of very affordable models such as the DSO Nano 3 and the JYE Tech DSO150 build-it-yourself kit.

[Thanks to BaldPower for the tip.]

The Diaphragm Is The Coil In These Flexible PCB Speakers

September 21, 2018 by 10 Comments

Speakers used to be largish electromechanical affairs, with magnets, moving coils, and paper cones all working together to move air around in a pleasing way. They’ve gotten much smaller, of course, small enough to screw directly into your ears or live inside the slimmest of smartphones and still delivery reasonable sound quality. The basic mechanism hasn’t changed much, but that doesn’t mean there aren’t other ways to make transduce electrical signals into acoustic waves.

Take these speakers made from flexible printed circuit boards, for instance. While working on his flexible PCB soft actuators, [Carl Bugeja] noticed that the PWM signals coursing through the coils on the thin PCB material while they were positioned over a magnet made an audible beeping. He decided to capitalize on that and try to make a decent speaker from the PCBs. An early prototype hooked to a simple amplifier showed promise, so he 3D-printed a ring to support the PCB like a diaphragm over a small neodymium magnet. The sound quality was decent, but the volume was low, so [Carl] experimented with a paper cone attached to the PCB to crank it up a bit. That didn’t help much, but common objects acting as resonators seemed to work fairly well. Check out the results in the video below.

This is very much a work in progress, but given [Carl]’s record with PCB creations from robotic fish to stepper motors built right into the PCB, we’d say he’ll make substantial improvements. Follow his and others’ progress in the Musical Instruments Challenge part of the 2018 Hackaday Prize.

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Easy GUI Front Ends For Arduino, Rasberry Pi, And More With MyOpenLab

September 21, 2018 by 24 Comments

If you want to integrate a nice graphical interface with a microcontroller or single-board computer for a useful piece of custom equipment, how will you go about it? MyOpenLab is a platform that makes it easy to design virtual interfaces your electronic builds. If you want controls and readouts for Arduino, Raspberry Pi, Android, or anything with a serial port, this is worth a try.

MyOpenLab reminds me of LabView. Not so much modern LabView with all of its add-ons and extras, but LabView back when it did just a few things but did them really well. The open source MyOpenLab project has been around for a while. The website and documentation are not in English, which may have kept some people from giving it a try, but the software itself is available in German, English, and Spanish. I took the plunge and found the language barrier didn’t cause me trouble.

As an example of what you can do, image you want to build a custom bench tool. You build virtual device (they call it a “VirtualMachine”) that uses your computer as the control panel and readout, and your electronic project as the physical interface. In myOpenLab your device will consist of two parts: a diagram and a front panel. Some things only live on the diagram, like a timer or a connection to an Arduino. But some things live on both like switches, LEDs, graphs, and so on. You can connect all the little boxes together to build up applications. They can stand alone, but the power comes in being able to connect to an Arduino or Raspberry Pi (or a few other options) for I/O.

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Convince Your Boss To Send You To Supercon

September 21, 2018 by 6 Comments

The Hackaday Superconference is rapidly approaching and you need to be there. The good news is, if you play your cards right you can get your boss to sign off on sending you to Supercon as part of your professional development.

This is the Ultimate Hardware Conference. This is your chance to recharge your batteries and come back energized for an amazing year ahead. You’ll be among hundreds of people who love to push the boundaries of what is possible. Dozens of talks and workshops take place over the backdrop of three days worth of a Hacker Village atmosphere focusing on a badge hacking demoscene.

We’re here to help you get to yes with the powers that be in your company. If you have a tight set of requirements that dictate what counts as professional development, we have a template to use in formulating your ask. Fill in this letter with the details that work for you and head over to the corner office with this in hand.

If you already have a supervisor who understands the hacker lifestyle, the best route is to show off the best Supercon has to offer. Share the playlist of talks from 2017 with them and you’re a shoe-in for your company’s conference attendance budget. And while you’re at it, try to convince your boss to come along for the fun!

See you in November!

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Prusa Unveils Their Own Line Of PLA Filament

September 21, 2018 by 33 Comments

There’s little debate that the Original Prusa i3 MK3 by Prusa Research is just about the best desktop 3D printer you can buy, at least in its price bracket. It consistently rates among the highest machines in terms of print quality and consistency, and offers cutting edge features thanks to its open source iterative development. Unless you’re trying to come in under a specific budget, you really can’t go wrong with a Prusa machine.

But while the machine itself can be counted on to deliver consistent results, the same can’t always be said for the filament you feed into it. In a recent blog post, [Josef Prusa] explains that his team was surprised to see just how poor the physical consistency was on even premium brands of 3D printer filament. As a company that prides itself with keeping as much of the 3D printing experience under their control as possible, they felt they had an obligation to do better for their customers. That’s why they’ve started making their own filament which they can hold to the same standards as the rest of their printer.

Their new filament, which is aptly called “Prusament”, is held to higher physical standards of not only diameter but ovality. Many manufacturers simply perform spot checks on the filament’s diameter, but this can miss bulges or changes in its cross-sectional shape. On your average 3D printer this might cause some slightly uneven extrusion and a dip in print quality, but likely not a failure. But the Prusa i3 MK3, specifically with the Multi Material upgrade installed, isn’t most printers. During testing even these slight variations were enough to cause jams.

But you won’t have to take their word for it. Every spool of Prusament will have a QR code that points to a page which tells you the exact production date, length, percent ovality, and standard diameter deviation of that particular roll. An interactive graph will even allow you to find the filament’s diameter for a specific position in the spool, as well as determine how much filament is remaining for a given spool weight. It should be very interesting to see what the community will do with this information, and we predict some very interesting OctoPrint plugins coming down the line.

Prusament is currently only available in PLA, but PETG and ASA variants are coming soon. You can order it now directly from Prusa Research in Prague for $24.99 per kilogram, but it will also be available on Amazon within the month for help keep the shipping costs down.

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The N64 Controller Gets Brass Gears Through 3D Printing

September 21, 2018 by 36 Comments

The controller for the Nintendo 64 is a masterpiece of design, and despite being more than two decades old, people are still using this controller competitively. Smash Bros, you know. Those competitive gaming enthusiasts are hard on their controllers, and after decades and tournaments, the analog stick will wear out. Previously, this required a rebuild or simply replacing the entire controller. Now there’s another option: a completely re-engineered analog stick, all made possible thanks to 3D printing.

[Nam Le] is a student at Cal Poly, and as would be expected for a very specific subset engineering students, had to track down new N64 controller every few months. The stick on these controllers wear out, so [Nam] decided to make the most durable joystick that has ever fit inside an N64 controller.

The design of the N64 stick is pretty simple, and exactly what you would expect if you’ve ever opened up an analog joystick. There’s the stick itself, which is connected to gears on the X and Y axes, which are in turn connected to encoders. This entire assembly sits in a bowl. After twenty years, the mating surface between the stick and the gears wear down, and the bowl becomes deformed. The solution here is obviously to engineer something sturdier, and despite what most of the 3D printing community will tell you, ABS and PLA just won’t cut it.

[Nam] re-designed the gears and bowl out of brass using lost-wax casting using 3D printed parts. These brass parts were mated with 3D printed gears and an enclosure for the bowl. The stick is nylon, an important design choice because this is the first part to wear down anyway, and it’s also the easiest part to replicate. Yes, this is designing an analog stick for the strength of materials and Real Engineering™ for those of you keeping track at home.

Right now, the joystick works as intended, and lasts much longer than the stock version. The goal now is to get this stick tournament-legal for some serious Smash time, in the hopes of not replacing controllers every few months.

555 timer circuit robot

555 Timer Robots Will Rule The World

September 21, 2018 by 21 Comments

A running joke we see in the comments by Hackaday readers whenever a project includes an Arduino or Raspberry Pi that seems like overkill is to proclaim that “I could have done it with a 555 timer!” That’s especially the case if the project amounts to a blinking light or anything which oscillates. Well [Danko Bertović] has made a whole robot out of a 555 timer circuit in his latest Volos Projects video.

Okay, it’s really a dead bug circuit in the shape of a robot but it does have blinking lights. We also like how the base is the battery, though some unevenness under it seems to make the whole thing a bit unstable as you can see in the video below. There are also a few parts which are cosmetic only. But it’s cute, it’s a 555 timer circuit, and it’s shaped like a robot. That all makes it a win.

We do wonder how it can be taken further. After all, a walk cycle is a sort of oscillation so the 555 timer circuit could run some servo motors or at least some piezoelectric feet. Ideas anyone?

On the other hand, if you’re looking for a dead bug circuit which belongs in a fine arts museum then you need look no further than The Clock.

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