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Archive for the ‘flexible PCB’ Category

Tiny OLED displays are an absolute must-have in the modern parts bin, so what better way to show your allegiance to the maker movement than with a pair of Arduino-compatible OLED glasses? Created by Arduboy mastermind [Kevin Bates], these digital spectacles might not help you see any better — in fact, you’ll see a bit worse — but they’ll certainly make you stand out in the crowd at the next hacker con. (Whenever we can have one of those again, anyway.)

The key to this project is a pair of transparent CrystalFonts OLED displays, just like the ones [Sean Hodgins] recently used to produce his gorgeous volumetric display. In fact, [Kevin] says it was his success with these displays that inspired him to pursue his own project. With some clever PCB design, he came up with some boards that could be manufactured by OSH Park and put together with jewelry box hinges. Small flexible circuits, also from OSH Park, link the boards and allow the frames to fold up when not being worn.

The Arduglasses use the same ATmega32U4 microcontroller as the Arduboy, and with a few basic controls and a small 100 mAh rechargeable battery onboard, they can technically run anything from the open source handheld’s extensive software library. Of course, technically is the operative word here. While the hardware is capable of playing the games, [Kevin] reports that the OLED displays are too close to the wearer’s eyes to actually focus on them. That said the ability to easily create software for these glasses offers plenty of opportunity for memes, as we see in the video below.

For reasons that are probably obvious, [Kevin] considers the Arduglasses an experiment and isn’t looking to turn them into a commercial product or kit. But if there’s interest, he’s willing to put the design files up on GitHub for anyone who wants to add a pair of Arduino glasses to their cyberpunk wardrobe.

We all have a gaming system in our pocket or purse and some of us are probably reading on it right now. That pocket space is valuable so we have to budget what we keep in there and adding another gaming system is not in the cards, if it takes up too much space. [Kevin Bates] budgeted the smallest bit of pocket real estate for his full-size Arduboy clone, Arduflexboy. It is thin and conforms to his pocket because the custom PCB uses a flexible substrate and he has done away with the traditional tactile buttons.

Won’t a flexible system be hard to play? Yes. [Kevin] said it himself, and while we don’t disagree, a functional Arduboy on a flexible circuit makes up for practicality by being a neat manufacturing demonstration. This falls under the because-I-can category but the thought that went into it is also evident. All the components mount opposite the screen so it looks clean from the front and the components will not be subject to as much flexing and the inputs are in the same place as a traditional Arduboy.

cost = low, practicality = extremely low, customer service problems = high

     ~[Kevin Bates]

These flexible circuit boards use a polyimide substrate, the same stuff as Kapton tape, and ordering boards is getting cheaper so we can expect to see more of them popping up. Did we mention that we currently have a contest for flexible circuits? We have prizes that will make you sing, just for publishing your flex PCB concept.

[Thank you for the tip, c00p3r]

[Micah Elizabeth Scott] needed a custom USB keyboard that wrapped around a post. She couldn’t find exactly what she wanted so she designed and printed it using flexible Nijaflex filament. You can see the design process and the result in the video below.

The electronics rely on a Teensy, which can emulate a USB keyboard easily. The keys themselves use the old resistor divider trick to allow one analog input on the Teensy to read multiple buttons. This was handy, but also minimized the wiring on the flexible PCB.

The board itself used Pyralux that was milled instead of etched. Most of the PCB artwork was done in KiCAD, other than the outline which was done in a more conventional CAD program.

We always enjoy seeing practical use of hacker-grade 3D printers. After all, there are only so many keychains you can make. Of course, you probably don’t need exactly this keyboard layout. But the techniques of creating the flexible PCB, printing the keypad itself and integrating everything with the electronics would be a great road map for any similar project.

As far as we can tell, the cat made no actual contribution to the final design. Unless you count inspiring flexibility, perhaps.

We’ve seen people make the actual PCBs using Pyralux and Ninjaflex as an etch resist if you don’t want to mill the boards. This isn’t the first time we’ve seen a Teensy pressed into keyboard controller service, either.

Thanks [Kyle] for the tip.


Filed under: 3d Printer hacks, Arduino Hacks, ARM


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