Touch Sensors

@thetechnobear that’s really excellent, thank you so much!

I won’t try to say that DIY capacitive touch is easy, but you don’t need 16 channels of audio I/O. Randy’s prototype used 8 channels of I/O and is very impressive! Also, folks have used his DIY instructions with as little as the stereo headphone jack and stereo microphone jack of the typical laptop. That’s enough for 4 capacitive plates and pure interpolation to sense position and pressure up to the limits of the signal-to-noise and bit depth used.

Granted, if you want to build something as large as the Soundplane Model A, you’ll need more than stereo I/O. The Soundplane has a 64x8 grid using 32 output and 16 input channels, stacked.


I’d rather not use Max and and audio interface for this. Would prefer a more permanent solution.

Can’t argue with that. I merely wanted to point out that it’s easier than finding a 16-channel audio interface. But, yes, much better to spend less time building your instrument so you’ll have more time to play it.

I mean, if I thought I had a better idea than Soundplane, Linnstrument, Continuum, Etouché, or Seaboard, that would be a different story. But I’m pretty sure I don’t.

Bumping an old thread for an interesting announcement via the Max newsletter today.
I hadn’t paid any real attention to the Sensel Morph but the Max package for it has got me interested.
Seems like a reasonably priced way to get some great touch data for Max to use.

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6 posts were split to a new topic: Dudes fsr box run

wrong thread confusion

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yeah that’s weird

we’ll look into it

Has anyone here played around with making their own capacitive touch controller using the mpr121 and arduino? I have played around using adafruit’s library and almost have a simple Buchla style controller figured out. I’m just having a lot of trouble getting pressure right.

I worked with BareConductive on PiCap ( → here’s our mpr121 code: — maybe it will be useful in some way?

I’ll take a look at it. Thank you!

I’ve been using the capacitive touch library on Arduino Playground, it’s been really easy for me to work with.

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Any recomendarions for a good dac, maybe dual or quad to use with touch sensors and an arduino? Without being a smd…

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A couple of years have passed - has anyone used the Sensel Touch for their own projects eg. with Bela or Teensy, using the serial interface, and could share any experiences? I saw there are some example projects and instructions on installing the serial library on the BBB / Bela image, and so on, more interested in whether people in here have made anything finished for themselves with a combo like that.

I’ve had this idea going around in my head for a while for a multi touch type instrument, and was initially keen to try out some of the DIY sensing ideas discussed in this thread too, but being lazy and time-constrained, I ended up thinking it’d be wiser to use Morph and something like a beefier MCU board or a BBB + Bela for prototyping so I could actually get to the “getting something working” part of the project eventually.


@kbra, sounds like a cool project! Can you help me understand what advantages a serial interface might have over using MPE?

Can you help me understand what advantages a serial interface might have over using MPE?

The short subjective answer is “for this case, I don’t know yet” :slight_smile:

The longer answer is that with MPE you get note on / note off events and a couple of MIDI resolution CCs based on how your touches are interpreted and converted to MIDI data on the device. With the serial interface you get closer to raw sensor data: information about individual touches, their area, force, shape etc., and it’s up to you to interpret what they mean and how the instrument should act based on them. So it’s kind of two abstraction levels to choose from, both good for certain types of control.

(Plus the serial protocol transfers data somewhat faster than normal MIDI spec - so I’d assume that at least in theory it’s possible to have less latency between the point when a touch is registered and when something happens on the synthesis side.)

One example being, that for a waveguide / modal / similar physical modeling instrument you could have one large playing surface that responds to exciting differently on different spots, allows for scraping the surface, et cetera. At least in my head it’d be easier to implement that level of control just by interpreting touch data across the surface directly, than to first transfer that to MIDI notes and CCs + poly pressure.

Whether these things matter in my specific use case or if eg. MPE would be expressive and responsive enough I don’t yet know. That’s sort of why I’m curious how other people have used these as I haven’t bought a Bela & a Morph (yet), and that’s one thing that I’d like to figure out if I end up trying out the idea.


Jack Armitage, from the Augmented Instruments Lab at QMUL, did work on some examples for using the Sensel Morph with Bela a few years ago.

Thanks! I should have mentioned that I stumbled upon that very repository, which (together with realizing that the Morph has an open source API / library and a developer serial cable) kind of sparked the idea in the first place. I’ll definitely be starting my learning from those examples if / when I get the hardware setup first.


Thanks! That really helps.

Moderators, ahoy!
I didn’t want to unilaterally make the decision, but would it be Ok if I started a dedicated Sensel Morph thread. There are several Morph with this, and Morph with that topics, but as far as I can see, none devoted entirely to the Morph.
Please advise.


Please do! I have one and would love some good conversations about it.