Some accidents are happy accidents. In this case, the accident happened to be dropping a surface mount resistor into a hole on a PCB. It fit perfectly, which gave Kevin Bateske the inspiration to incorporate this concept into a project.
The lucky recipient of this design method was the Arduboy, an Arduino-based game system with capacitive touch buttons and an OLED screen. The screen happened to be roughly the same thickness as the PCB, and so was the battery. Having these multiple components suspended in cutouts would surely be a striking visual concept.
A prototype using a Qdoba card.
Bateske prototyped the idea in a few different ways and ultimately designed a PCB. His order came in, and he found it almost perfect. The only unfortunate issue was that the spot for the AtMega was not milled out. A friend help cut a nice, clean opening, and if Bateske didn't tell you that it wasn't professionally done, you wouldn't even know it.
Hand-cut hole for the AtMega.
He has not released the files for the Arduboy yet; he says he would like to use crowdfunding to make the necessary changes to make this a releasable project. The reason for the additional cost is to get a license for Cadsoft Eagle, as well as cleaning up the code and improving the design.
On the list of improvements, he mentions that he should probably switch to resistive touch sensors. Capacitive sensors are interesting and can supply force measurements, but they aren't as reliable as resistive ones.
Yes, hopefully a kickstarter in the next few weeks. I am trying very hard to find a manufactruer to mass-produce these. It will mean I don't have to limit production of assembled units and the overall price will likley go down. But no promises, this board has to be hand assembled so I've already had a board house decline to bid.
@Kevin: I LOVE it -- I want one!!! Are you planning on launching a Kickstarter project to crowd-fund this? EE Times blogger Duane Benson and I are in the process of launching our own Kickstarter project -- email me at max@CliveMaxfield.com if you have any questions.
Kevin Bates here, maker of the Arduboy! Thank you so much for covering this Caleb, I enjoyed your previous writing at your old outlet!
The microcontroller has very good built in protections on the input pins. It is surprisingly rugged. I have kept it in my wallet for a week now without any problems.
In fact I will probably post a video of me rubbing it on a carpet or some such thing. I'm interested to see how far it you can push your luck.
On the more reasonable side of things, it's probably a good idea to put some polyamide tape or some other kind of insulating material on the back of the card. I have plans to offer vinyl stickers with different designs and of course also the files you need to make stickers of your own!