Communicating with several Sensel Morphs

#1

Hi folks!

Looking forward to build a DIY instrument out of several (four) Sensel Morphs (not available yet - but soon!). And I am thinking about using the Axoloti as "brain", which would be awesome as it brings a full fledged synth and midi and audio out. (Optimally I would just have to write one custom Axoloti midi processing module)
I am not sure though whether/how I get more than one Morph connected to the Axoloti. The morphs offer MIDI over USB, and for Arduino there is a USB to serial cable available. Now the Axoloti has MIDI USB host functionality - but USB hubs are not supported, right? And the Axoloti doesn't seem to have the additional serial inputs like e.g. the Arduino Mega.

So, is there a chance to get four Morphs connected to an Axoloti?

Thanks and all the best,
Ferdinand

#2

I asked a similar question, albeit for DIN , but the answers are relevant.

the other thing to be careful of, is Axoloti doesn't support USB 2.0, not sure if that is an issue for Sensel Morphs or not.

#3

Thanks Mark,
a lot of interesting infos in this thread!
Was hoping for a one device fits all solution, but e.g. adding an Arduino Mega for four additional UARTs sounds like not too much overhead.
Thanks for the hint regarding USB2, will have to investigate (as the serial to USB cable that comes with the "Inventor Morph Overlays" are specifically for Arduino the Mega should be able to handle it - assuming I go with the Mega-in-between solution...)

Still some time to experiment with options until the Morphs arrive :slight_smile:

Best,
Ferdinand

#4

Hi Ferdinand... I thought it might be you but didn't recognise the userid :slight_smile:

I think with this microcontrollers, its quite common to use a few of them in tandem, and I've now seen a few scenarios where the sound engine is done on one, and the other controller handling (knobs/buttons/sliders) done on another. then perhaps communication via SPI.

so have Sensel revealed what the usb protocol is for the morph? could be quite alot of data to sift thru to deduce the touches ... are they going to open source a touch tracker?

looking forward to hearing about your explorations!

#5

Yep, it's me, tried to register NothanUmber first but ocurrently entered a typo into my email address, so this pseudo is now reserved. Whatever :slight_smile:
The Morph uses actually different protocols, depending on the preset/overlay. There will be an editor where you can place different elements onto your layout. And each of these elements speaks a distinct protocol (sent over either USB or Bluetooth). So MIDI objects speak MIDI (if you only use MIDI objects the Morph is a MIDI class compliant client). Not sure which events they will use and how they handle poly expressions though (MPE would be nice..)
If you use gamepad elements (like joysticks or buttons), touch or mouse areas these will work as a corresponding HIDs. So in many cases you don't need Morph specific drivers.
And last but not least there is a "raw mode" that just sends the raw data in a custom format. They have an API for Windows/Mac and Linux that reads this protocol - should not be too difficult to adapt to Arduino, the full source code is available here: https://github.com/sensel/sensel-api-c-cpp
Don't know much about the capabilities of their MIDI objects but if they don't do what I need then raw mode sounds like the way to go.

Also looking forward to this - have added a few new ideas since the last revision... :slight_smile:

Best,
Ferdinand

#6

ah, I didn't realise it had enough 'processing onboard' to be able to support different protocols - nice!
(I had assumed the protocol 'conversion' would be done on the computer)

its an exciting product, and the tech is can be used for much larger surfaces (apparently) if they can make a success of it. so definitely hoping to hear good things about it.

(must be close to shipment now? no?)

#7

I takes slighly longer because they wanted to add some hardware enhancements. (Even higher max resolution, so now we have the choice between 128 Hz / 8 ms latency highres or 500 Hz / 2 ms latency standard resolution. And - most important for several side-by-side-Morphs - margin-less horizontal tracking up to the outer borders). They plan to ship in October (2016 :wink: ) now.
Edit: different form factors are planned. Fingers crossed that they will release a 4-5 times longer version at some point. Then the instrument wouldn't be foldable anymore though, so I guess both variants have their merrits...
Edit2: Afaik the firmware won't be open source (initially at least), so we can only compose layouts out of the elements and configuration options they provide us - or use the API to process what they send as "raw data".

#8

yeah, this was the reason I held off... as I would prefer a larger form factor (, that and the fact i have way to many 'projects on the go' :))

higher resolution and margin less border is very useful... I'll be interested to hear how the latency pans out, 2ms I think will be fine, slower (for musical use) might be problematic, but perhaps not.

I think they will be pretty successful, appealing to graphic artists as well as musicians, expands there market a lot. (and of course, even other possibilities too) , its one of those products, if mass production can reduce costs, you could see someone like apple/microsoft buying them out to take the tech.

#9

Yepp, we will see how resolution vs latency/jitter goes. At high res it's supposed to have 0.1 mm tracking accuracy, so if the "speed mode" is achieved by only scanning every second sensor horizontally and vertically we would be at - hm - about 0.2 mm? - which would still sound nice on paper. And iPads that are frequently used for music apps are afaik scanning with 60 Hz, so even the high res mode would be twice that.
Will be interesting how the paper specs will translate to the real device - I will find out :slight_smile: