arduino_midi_library VS Control-Surface

take a look here

The Arduino MIDI Library [1]. Back in 2009, I learned C++ to build it and control my guitar effects pedals with custom electronics as part of my engineering degree.

[1] https://github.com/FortySevenEffects/arduino_midi_library

Your project can be broken up into a number of subprojects. For keyscanning you don't need additional hardware, just the pins from the ribbon cables going to the arduino's digital pins and ground. Since the keys are just switches (two per key, the time difference between the two switches closing giving the source of velocity), you could start with some examples from the Arduino MIDI library (https://github.com/FortySevenEffects/arduino_midi_library). To test MIDI sending you don't even need to start from the keybed just yet, and if you do, you can start with a single key. Once you've got that part figured out end to end (key press/release generates note on/off events) you can work on iterating through the matrix, CC controls etc. MIDI out can be done in different ways. With a 5 pin DIN plug you'd just need two 220 ohm resistors.

On an Arduino compatible platform the configuration of the baud rate at the bare metal layer is taken care of by the library when you call its begin() method. Looking at the example code included with the library it appears that there are no timer interrupts or anything like that required of you in order to use it. Another thing that jumps out is that the call to read() returns a non-zero value if anything has been received that you should use to predicate whether any further attention needs to be spent on it by your code. You may know this but it wasn't apparent from the loop() { MIDI.read\`() }` example that you gave above.

As i have started to combine this with Midi Implementation from FourtySevenEffects lib, i only have done a quick test with two/three strips and did discover follwing issue(s):

Using a library for the midi shield you can register two functions as callbacks. One callback for NoteOn(...) messages and one for NoteOff(...) messages. But thre is much more. In the end the source of truth should always be the docs for the library itself.

Click the link to github (second link in the article) and there's all the source code: https://github.com/FortySevenEffects/arduino_midi_library

Here’s a library that might work.

Solution from GitHub here:

I was in a similar boat to you, though I have a lot of experience programming outside of the arduino/midi controller context. I was pretty happy to just use https://github.com/tttapa/Control-Surface as a library to handle connecting an arduino with a pot to my PC as a midi controller. The docs and examples the codebase has were very useful.

Wow, what a pretty project! If you end up expanding this, you might look at the Control-Surface lib; seems like it's made for this kind of thing.

https://github.com/tttapa/Control-Surface

I've been working on this beasty project together with a friend. We did some liveshows back then and decided that we needed some more control gear. But not just a laptop focusing launchpad, we wanted to forget there was even a laptop (or other hardware) attached to this controller, so that all our attention and focus would be on the music and the crowd, and above all: we wanted something that would instantly announce your presence on stage.

I used this library with an Arduino and several multiplexers. It worked very well and was easy to use. https://github.com/tttapa/Control-Surface

Should be fixed in https://github.com/tttapa/Control-Surface/commit/eb7a468a0a73584b93be16d978404b25401ce66f, you can increase the SELECT_LINE_DELAY constant if necessary.

The PCB was an entirely new endeavour for me, but it was essential in making the project footprint as small as possible. Never done any kind of electronics design outside of hobbyist arduino stuff and the initial prototype. I used [KiCAD 6] to design the PCB. KiCAD might be the single greatest GUI-based open-source software I have ever used, its a shame FreeCAD is so far behind it in terms of stability. It is also free and open source. I went with a simple 2 layer design with all through-hole components to keep things as simple as possible so people didnt have to mess around with heat guns or toaster ovens to solder the board. It turned out great. I also elected to use a teensy to do the heavy lifting. Sticking to an arduino platform means its a lot easier for people to contribute to the firmware. It also meant I could use the greatest arduino library ever written, Control Surface. Control surface is what makes it so easy to write the midi logic for the firmware. It is the backbone of the firmware and really is incredible.

Take a look at tttapa's control surface github! It's an extremely robust MIDI library so all you really need is a little Arduino/C knowledge and you should be able to get the inputs worked out. I'm a little fuzzy in my output understanding with MIDI, but this library supports that too! Understanding Keyboard matrices isn't hard once you wrap your head around the basics (I recommend looking up computer keyboard handwiring guides and/or qmk as there's a lot there and the wiring is the same)