[LAU] Touchpad to MIDI

Bill Purvis bill at billp.org
Tue Jul 27 10:42:24 CEST 2021

On 27/07/2021 09:33, Will Godfrey wrote:
> On Tue, 27 Jul 2021 10:03:33 +0200
> Lorenzo Sutton <lorenzofsutton at gmail.com> wrote:
>> Hi Will,
>> On 27/07/21 09:22, Will Godfrey wrote:
>>> Does anyone know of software that can generate MIDI messages from a touchpad?
>> If, as I understand it, you mean a latptop touchpad (i.e. thing used
>> instead of a real mouse with your finger :-) ) Pure Data can definitely
>> do it in many different ways.
>> The Pd 'vanilla' way would probably be using a canvas object(s) and
>> tracking movement as you 'drag' them around.
>> There are a bunch of Pd externals (i.e. libraries not included in Pd you
>> need to compile and install separately), which can also do this in
>> various ways. [1]
>> Once you have the touchpad detection / setting setup Pd has a set of
>> inclued midi sending obejects which are really easy to use to send CC,
>> notes etc.
>>> The idea would be to send CCs to a sequencer or soft synth, but being able to
>>> send it to an external hardware device would also be very useful.
>> MIDI objects receive/send alsa-midi so you can route them to any
>> sequencer, synth or hardware device which can receive alsa-midi.
>> Hope this helps.
>> Lorenzo.
>> [0] https://puredata.info/
>> [1] There is also a Pd 'distribution' which comes packed with many many
>> externals out of the box, Purr Data: https://www.purrdata.net/
> Thanks for all of this Lorenzo. I had been hoping for something lightweight,
> however if I can find that round tuit I seem to have lost, this is certainly an
> interesting (and potentially flexible) way of solving the problem.
> Will.
Anyone with a bit of programming skill could knock together something 
that would
send a CC event via the Jack interface - I've done stuff like this in 
the past.
You'd also need some familiarity with Xlib to get the keypad events.


| Bill Purvis                            |
| email: bill at billp.org                  |

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