In today’s “futuristic tech you can get for $5”, [RealCorebb] shows us a gesture sensor, one of the sci-fi kind. He was doing a desktop clock build, and wanted to add gesture control to it – without any holes that a typical optical sensor needs. After some searching, he’s found Microchip’s MGC3130, a gesture sensing chip that works with “E-fields”, more precise than the usual ones, almost as cheap, and with a lovely twist.
The coolest part about this chip is that it needs no case openings. The 3130 can work even behind obstructions like a 3D-printed case. You do need a PCB the size of a laptop touchpad, however — unlike the optical sensors easy to find from the usual online marketplaces. Still, if you have a spot, this is a perfect gesture-sensing solution. [RealCorebb] shows it off to us in the demo video.
This PCB design is available as gerbers+bom+schematic PDF. You can still order one from the files in the repo. Also, you need to use Microchip’s tools to program your preferred gestures into the chip. Still, it pays off, thanks to the chip’s reasonably low price and on-chip gesture processing. And, [RealCorebb] provides all the explanations you could need, has Arduino examples for us, links all the software, and even provides some Python scripts! Touch-sensitive technology has been getting more and more steam in hacker circles – for instance, check out this open-source 3D-printed trackpad.
Looks like another application of mm waves
this IC part (released by Microchip about 10 years ago), perform really well usig low frequencies (around 100k) in the near-field range, especially in terms of power consomption. Of course with mmwave you could build the same function, in this case based on far-feild. But exepted the detection range that could be extended in the ten meter range (with consumption tradeoff), I am not sure of the interest.
That said, I didn’t see a lot of products integrating thus 3D gesture sensor, may be some high end PCs?
Hardly. More like km waves. But nobody cares about 6 orders of magnitude here anyway.
That is really cool, I will have to keep that hw in mind
5€ is just the cheap. The 4-layers board likely exceeds that price tag. If anybody finds online a ready-to-use modules for less than 20 bucks (preferably euro-bucks), share !
The Flick! board has one. Found one cheap on ebay: https://www.ebay.co.uk/itm/256839229885?
Or really expensive, here: https://www.mikroe.com/gesture-board#/60-gesture_adapter-none
they should add an accelerometer to normalize up/down/left/right regardless of the sensor orientation.
Oh, yes, and add a servomotor to rotate the associated display too!
Impressive!
Is something like this usable when it is raining?
I wonder if this can be a competitor to the traditional laptop trackpads. They too are capacitance based iirc
I wonder if this could be added under a mechanical keyboard’s PCB, to allow the keyboard to be used as a trackpad when a certain key is pressed?
So, basically a Theremin. The single-chip solution makes it nice and easy.
There’s no reason the electrodes couldn’t be strips of copper tape on the backside of a lid. Or, since it’s really high impedance they could be printed in place in conductive filament.
I was thinking of selling my thermin. I haven’t touched it for ages.
Steven Wright, is that you?
i’m just looking for a trackpad replacement that isn’t sensitive to everything except my pointer finger. my belly a half inch to the side, my leg a half inch below, my non-contact fingers an inch up, my palm while i’m typing, the humidity in the air. i’ve never had a satisfactory laptop touchpad experience in my life.
i just want to perform a repeated motion and get the same result each time
kind of doubt this is what i’m looking for :)
When I worked at Microchip I pulled a few of these dev kits out of the e-waste. Always meant to embed one in my desk.
This subject keeps coming up lately, like when I installed an RF motion-sensing bulb in my foyer (basically never turned off due to sensing motion through wall), and when I’ve been using a VR headset with vision-based gesture controls (works surprisingly well, but gives constant spurious inputs if you try to use your hands as general-purpose hands).
We’ve had this kind of touchless control for over a century, and the reason it hasn’t taken off is that having to first move your finger to the button is actually a feature. It means the interaction is locked out when you’re not thinking about it. (Also, mechanical switches are extremely precise).
The potential I see for cheap touch and gesture controls is in /combining/ them with mechanical controls. Like, you gesture at a button to select an action, then press to trigger it. Or, while turning a dial you can stick your pinky out for fine adjustment.
This reminds me of a bit from Hitchhikers Guide to the Galaxy:
“The machine was rather difficult to operate. For years radios had been operated by means of pressing buttons and turning dials; then as the technology became more sophisticated the controls were made touch-sensitive–you merely had to brush the panels with your fingers; now all you had to do was wave your hand in the general direction of the components and hope. It saved a lot of muscular expenditure, of course, but meant that you had to sit infuriatingly still if you wanted to keep listening to the same program. “