Advice on a custom midi controller idea

Still · 2023-10-23T13:48:36.389Z

So I’ve had this idea/desire for a midi controller for awhile—
I want a small device that basically adds in-time drum ratcheting for drum machines (octatrack, digitakt, etc. ). For my current live setup, I use a Drumbrute impact which has this, but I am going to be removing it from my stop to free up inputs on my octatrack.

It would work similarly to how note repeat works on an mpc, though with the caveat that I want to design it for one handed operation, since I often am playing a keyboard or using the OT slider with my right hand. NOTE- I have been able to get this working with a beatstep pro, but that takes up a lot more real estate than I would like.

Some requirements (just sort of thinking out loud here):

one handed operation
latching (on or off) of repeat rate (so you don’t have to hold down both the rate selector as well as the note selector)
selectors for 1/4, 1/8, 1/16, 1/32 (maybe a button to switch between triplets and regular?)
probably 8 drum trigger buttons
midi ports in and out, and obviously able to receive midi tempo

The question: does anyone have suggestions for what platform to build this on? I have fairlyy minimal coding experience, so obviously I would love to build this on a system where code at least partially exists already. Are there raspberry pie projects already doing some of this that you know of, or other purpose built midi controller firmware/hardware that could be stretched to handle this?

Of course I’d also be open to collaborating with other folks if this is a project of interest!

the_duckchild · 2023-10-23T13:59:59.532Z

could use Teensy and this for building the midi controller part;

github.com

GitHub - tttapa/MIDI_controller: This is a library for creating a MIDI...

This is a library for creating a MIDI controller using an Arduino or Teensy board. - GitHub - tttapa/MIDI_controller: This is a library for creating a MIDI controller using an Arduino or Teensy board.

you then probably just need to work out some code for “keep sending MIDI notes at note division of MIDI clock until button repressed” or whatever. People will probably be pretty helpful here once you’ve had a go and got stuck:

https://forum.pjrc.com/

I’ve got pretty rudimentary coding skills and managed to build this sort-of-APC-40-rip-off-dub-mixer-controller using Teensy and the older version of that library:

https://www.instagram.com/p/BySJNnbHybz/

(side note: wow. I really had a lot of time on my hands before I was a parent.)

shigginpit · 2023-10-23T15:08:07.541Z

*edit: just as a quick update to my post I did a google search on a hunch and I found out that a Korg Volca beats with the midi out mod can output the stutter effect both time and length via midi (amongst a number of other unexpected midi features) and this might be the cheapest option with the least amount of desk space, the mod is pretty easy and I’m looking at my Volca beats like I might need to do this too.

Original post:

I’m positive this can be done with existing products in less time for equal cost and far less effort. Just off the top of my head I can think of a number of craft-made pint-sized midi controllers which I’ve seen on various “maker” oriented sites that are fully programmable and the size of like a small guitar pedal, there are also other similarly programmable units that can probably do something similar in a small size but might not have the controller built in. I think you should research this a bit more before you let the horse get away from you, unless you’re really into the idea of re-inventing the wheel.

Phantasmal Force >> micro MIDI controller

also BeatsAndButtons has some rather small and configurable controllers on here as well.

Also, I’d talk to the phantasmal force guy because it may be possible to program it for what you want, but even if it’s not a native capability of the controller, maybe contact this guy at MidiSizer who designed midigal (based on midipal) and see if the midigal arpeggiator (MidiArp) app can be configured to do what you want.
MidiGAL | MidiSizer

I think there are other options on the market, but midigal is a possibility and the first one that comes to mind (although with all the capabilities of midigal, it’s a bit under-using it as a tool, however in regard to size it’s right in line with what you want)

I don’t want to discourage you because if you are looking to make a dedicated device for this and have the time and drive to do so, I’m sure it’s possible as all things are possible, but in the opening post you say you have only minimal coding experience and you’re mainly driven by the desire to cut down on the space necessary to achieve what you want and it might be more manageable to throw a little money at this and be done with it. What you’re describing is a pretty big undertaking going from zero to “live set stable operation”.

the_duckchild · 2023-10-23T15:29:30.030Z

that’s totally fair - unless the thing you need doesn’t exist, or you’re into making things for making’s sake it is always a lot less money and hassle to just buy a thing.

Still · 2023-10-23T16:05:53.368Z

Thank you both for your thoughts on this! I am definitely not trying to reinvent the wheel if I don’t have to :))
I’ll check out those links later today when I have a chance to procrastinate from work a bit

shigginpit · 2023-10-23T16:12:59.592Z

If you want any links to the info about the volca beats mods (there are many) but specifically the midi mod let me know. Check out some youtube videos on the volca beats stutter and if that looks like it might be along the lines of what you want, it might be possible to get out of this for like $100 and just soldering 3 wires.

If you want more specific divisions like arturias keystep mod strip stuff, I think that midigal is probably going to be more capable of specific note divisions.

lowph · 2023-10-24T00:26:47.410Z

Yeah, Teensy could be a great choice for this.

@Still, here’s a friendly doc on using teensyduino
https://www.pjrc.com/teensy/td_midi.html

And here’s a library that can be used to build upon:

github.com

GitHub - joshnishikawa/MIDIcontroller: A library for creating Teensy MIDI...

master

A library for creating Teensy MIDI controllers with support for hold or latch buttons, potentiometers, encoders, capacitive sensors, Piezo transducers and other velocity sensitive inputs with after...