hardware

1822 Articles

Applied Science Rolls An Electroluminescent Controller

November 26, 2018 by 30 Comments

After LEDs and TFTs and OLEDs and liquid crystals, there’s another display technology that doesn’t get a lot of attention. Electroluminescent displays have been around for ages, and there still aren’t a whole lot of applications for them. That might change soon, because Applied Science a.k.a. [Ben Krasnow] figured out an easy way to build EL displays on anything, and created a simple circuit that’s capable of driving video on a remarkable blue phosphor EL display.

For this build, [Ben] is using a specialty product from Lumilor consisting of a copper-ish conductive base layer, a clear dielectric, the ‘lumicolor’ phosphor, and a clear conductive top coat. All of these layers are applied with an airbrush, and the patterns are made with a desktop vinyl cutter.  This is an entire system designed to put electroluminescent displays on motorcycle gas tanks and to have doors that go like *this* and glow. That said, the system isn’t very dependent on the substrate, and [Ben] has had successful experiments in creating EL displays on plastic sheets, 3D printed parts, and even paper.

Compared to previous (and ongoing) efforts to create EL displays such as [Fran]’s recreation of the Apollo DSKY, the Lumilor system seems extraordinarily easy and clean. Current efforts as with [Fran]’s example are using a silkscreen process, which is a mess no matter how you look at it and can’t be applied to non-flat surfaces.

But EL displays are more than just putting a few layers of chemicals on a substrate — you need to drive these displays with high-frequency, high-voltage AC. For this, [Ben] designed a multi-channel electroluminescent driver based on the Adafruit Trinket M0, two LT3468 ICs to generate a high voltage, and either a an HV507 or HV513 to drive 8 or 64 channels.

With the ability to create EL displays and drive 64 channels, there really was only one thing to do: a 32×32 display. Even seeing a few lines scan across a 32×32 EL display is magical, but it’s got another trick up its sleeve: it also plays a low-resolution video of Never Gonna Give You Up.

This isn’t a video to be missed, check it out below.

Continue reading “Applied Science Rolls An Electroluminescent Controller” →

Watch The Low-Cost Mechatronics Lab Dispense Candy, Sort Cups

November 26, 2018 by 5 Comments

A lot can be done with simple motors and linear motion when they are mated to the right mechanical design and control systems. Teaching these principles is the goal behind the LCMT (Low Cost Mechatronics Trainer) which is intended primarily as an educational tool. The LCMT takes a “learn by doing” approach to teach a variety of principles by creating a system that takes a cup from a hopper, fills it with candy from a dispenser, then sorts the cups based on color, all done by using the proper combinations of relatively simple systems.

The Low Cost Mechatronics Trainer can be built for under $1,000 and is the wonderful work of a team from the Anne Arundel Community College in Maryland, USA. The LCMT is clearly no one-off project; there are complete CAD files and build documentation on the site, as well as a complete lab guide for educators.

A demo video of the assembled system is embedded below, with a walkthrough done by [Tim Callinan]. It’s worth a watch to see how cleanly designed the system is, and the visual learners among you may learn a thing or two just by watching the system go through its motions.

Continue reading “Watch The Low-Cost Mechatronics Lab Dispense Candy, Sort Cups” →

Put That DLP Printer To Use Making PCBs

November 24, 2018 by 38 Comments

Now that these DLP printers are cheaper and more widely available, we’re starting to see hackers poking around the edge of the envelope to see what else the machines are capable of. [Electronoobs] recently got his hands on a couple of these printers, and thought he would do some experiments with using them for PCB production.

Rather than extruding molten plastic, these printers use light to cure resin layer-by-layer. In theory if the printer is good enough to cure the light-activated resin for a high resolution print, it should be able to do much the same thing with photosensitive PCBs.

Unfortunately, getting an STL out of a PCB design program takes a few intermediary steps. In the video after the break, [Electronoobs] shows his workflow that takes his design from EasyADA and turning it into a three dimensional object the DLP printer will understand. He does this with Blender and it looks pretty straightforward, but in the past we’ve seen people do similar tricks with Inkscape if that’s more your style.

Once you’ve grafted another dimension onto your PCB design, you may need to scale it to the appropriate size. [Electronoobs] notes that his STL for a 60 mm wide PCB came out of Blender as less than 2 mm wide, so you might need to break out the dreaded mathematics to find the appropriate scale value. Once the dimensions look good, you can load this file up into the printer as you would any normal print.

On the printer side of things, [Electronoobs] manually laminates UV photoresist film onto some copper clad boards with an iron, but you could skip this step and buy pre-sensitized boards as well. In any event, you drop the board where the UV resin normally goes, press the print button, and wait about ten minutes. That should give it enough time to expose the board, and you then proceed with the normal washing and acid bath process that hackers have been doing since time immemorial.

As [Electronoobs] shows, the results are quite impressive. While this still won’t make it any easier for you to do double-sided PCBs in the home lab, it looks like a very compelling method for producing even SMD boards with relative ease. This isn’t the first time somebody has tried using a DLP printer to run off some PCBs, but now that the technology has matured a bit it looks like it’s finally becoming practical.

Continue reading “Put That DLP Printer To Use Making PCBs” →

Energy Sipping Neodymium Sphere Keeps On Spinning

November 23, 2018 by 16 Comments

At this point we’re sure you are aware, but around these parts we don’t deduct points for projects which we can’t immediately see a practical application for. We don’t make it our business to say what is and isn’t worth your time as an individual hacker. If you got a kick out of it, great. Learned something? Even better. If you did both of those things and took the time to document it, well that’s precisely the business we’re in.

So when [Science Toolbar] sent in this project which documents the construction of an exceptionally energy efficient spinning neodymium sphere, we knew it was our kind of thing. In the documentation it’s referred to as a motor, though it doesn’t appear to have the torque to do any useful work. But still, if it can spin continuously off of the power provided by a calculator-style photovoltaic cell, it’s still a neat trick.

But how does it work? It starts by cracking open one of those little solar powered toys; the ones that wave or dance around as soon as any light hits the panel in their base. As [Science Toolbar] explains, inside these seemingly magical little gadgets is a capacitor and the classic black epoxy blob that contains an oscillator circuit. A charge is built up in the capacitor and dumped into a coil at roughly 1 Hz, which provides just enough of a push to get the mechanism going.

In the video after the break, [Science Toolbar] demonstrates how you can take those internals and pair it with a much larger coil. Rather than prompting a little sunflower or hula girl to do its thing, the coil in this version provides the motive force for getting the neodymium sphere spinning. To help things along, they’re even using a junk box zero friction magnetic bearing made up of a wood screw and a magnetized screwdriver tip.

It’s an interesting example of how a tiny charge can be built up over time, and with a nice enough enclosure this will make for a pretty cool desk toy. We’ve previously seen teardowns of similar toys, which revealed a surprising amount of complexity inside that little epoxy blob. No word on whether or not the version [Science Toolbar] cannibalized was quite so clever, however.

Continue reading “Energy Sipping Neodymium Sphere Keeps On Spinning” →

Many Ways To Drive A Small Motor

November 19, 2018 by 17 Comments

Tiny motors used for haptic feedback and vibration come in a variety of shapes and sizes. The most familiar is the “eccentric rotating mass” (ERM) variety which just spins an imbalanced weight on a small motor and comes packaged in two form factors. The classic is the pager “pager motor” which just looks like a tiny, adorable motor and the squat cylindrical “pancake style”. ERMs are simple to use but provide imprecise response when compared to their new-age cousin the “linear resonant actuator”. Unlike the motor in an ERM, LRAs are typically an enclosed mass on a spring placed near a coil which pushes the mass back and forth. The name LRA might not be familiar but Apple’s branded implementation, the Taptic Engine, might be a little more recognisable.

[Precision Microdrives] is a vendor of these sorts of devices who happens to have a pleasantly approachable set of application notes covering any conceivable related topic. A great place to start is this primer on ways to drive motors with constant voltage in a battery powered environment. It starts with the most simple option (a voltage divider, duh) and works through a few other options through using an LDO or controller.

If you’re thinking about adding haptics to a project and are wondering what kind of actuator to use (see: the top of this post) AB-028 is a great resource. It has a thorough discussion on the different options available and considerations for mounting location, PCB attachment, drive modes, and more. Digging around their site yields some other interesting documents too like this one on mounting to fabric and other flexible surfaces. Or this one on choosing PWM frequencies.

Of Roach Killer And Rust Remover: Sam Zeloof’s Garage-Made Chips

November 19, 2018 by 28 Comments

A normal life in hacking, if there is such a thing, seems to follow a predictable trajectory, at least in terms of the physical space it occupies. We generally start small, working on a few simple projects on the kitchen table, or if we start young enough, perhaps on a desk in our childhood bedroom. Time passes, our skills increase, and with them the need for space. Soon we’re claiming an unused room or a corner of the basement. Skills build on skills, gear accumulates, and before you know it, the garage is no longer a place for cars but a place for pushing back the darkness of our own ignorance and expanding our horizons into parts unknown.

It appears that Sam Zeloof’s annexation of the family garage occurred fairly early in life, and to a level that’s hard to comprehend. Sam seems to have caught the hacking bug early, and by the time high school rolled around, he was building out a remarkably well-equipped semiconductor fabrication lab at home. Sam has been posting his progress regularly on his own blog and on Twitter, and he dropped by the 2018 Superconference to give everyone a lesson on semiconductor physics and how he became the first hobbyist to produce an integrated circuit using lithographic processes.

Continue reading “Of Roach Killer And Rust Remover: Sam Zeloof’s Garage-Made Chips” →

Flywire Circuits At The Next Level

November 19, 2018 by 40 Comments

The technique of assembling circuits without substrate goes by many names; you may know it as flywiring, deadbugging, point to point wiring, or freeform circuits. Sometimes this technique is used for practical purposes like fixing design errors post-production or escaping tiny BGA components (ok, that one might be more cool than practical). Perhaps our favorite use is to create art, and [Mohit Bhoite] is an absolute genius of the form. He’s so prolific that it’s difficult to point to a particular one of his projects as an exemplar, though he has a dusty blog we might recommend digging through [Mohit]’s Twitter feed and marveling at the intricate works of LEDs and precision-bent brass he produces with impressive regularity.

So where to begin? Very recently [Mohit] put together a small wheeled vehicle for persistence of vision drawing (see photo above). We’re pretty excited to see some more photos and videos he takes as this adorable little guy gets some use! Going a little farther back in time there’s this microcontroller-free LED scroller cube which does a great job showing off his usual level of fit and finish (detail here). If you prefer more LEDs there’s also this hexagonal display he whipped up. Or another little creature with seven segment displays for eyes. Got those? That covers (most) of his last month of work. You may be starting to get a sense of the quality and quantity on offer here.

We’ve covered other examples of similar flywired circuits before. Here’s one of [Mohit]’s from a few years ago. And another on an exquisite headphone amp encased in a block of resin. What about a high voltage Nixie clock that’s all exposed? And check out a video of the little persistence of vision ‘bot after the break.

Thanks [Robot] for reminding us that we hadn’t paid enough attention to [Mohit]’s wonderful work!

Continue reading “Flywire Circuits At The Next Level” →