This is version 2. This is my first foray into Arduino and diy midi programming. I have developed my prototyping and design skills, so I think it will be a good demo of the process and progress. In a more sensible design process, I recycled the button from my first attempt and started building 2. 0! My version 1st uses Arduino Mega because it has a lot of intput, but I like the small size and HID MIDI features of Pro Micro when using MIDI _ controller. h library. So I decided to use two 16. Channel MUX meeting 2-input requirements Eight Degrees in range. Here is a list of the parts I have used: big arcade keys x15 small arcade keys x10Pro micro x216- Multiplex x2Neopixel ring10k potentiometer x6Hookup wiresoering tools1/8-12 inch MDFI item. You can use svg files to query ideas if they are useful, but I encourage everyone to extract ideas and experiments during the design process. Maybe it would look great to replace the fiber board with acrylic! I used drill bits and drill bits in version 1st, so this time I would like to get more precise products using design software and laser cutting machine. This is the most time consuming part. I found certain parts of the welding treatment, so drink some tea and put on smooth jam and know that this step is a marathon, not a sprint! I\'m trying to salvage as many wires as I can from version 1st and note where I\'m going to put Arduino and mux in order to try and eliminate some wire quality to squeeze into the box when it\'s done. I tend to accept the confusion of a good diy winding wire, so follow your own ambitions when tidying up the wire. As far as the connection drill is concerned, write the code first, and then let it decide the direction of the wire. . . I built the keyboard with 1st 16 notes to mux1, the rest of the notes to mux2, the delay in mux settings may have increased slightly, but the 16-note mhz processor is fast enough through it, so I didn\'t notice. Before any tutorial, I tried to dig deeper into midi reuse and hit the wall, so I suggest doing some basic tutorials to get a baseline understanding if things seem out of reach. I follow the following simple troubleshoot steps: 1. Make sure everything goes well. Check shorts3. Pots get 5v4. Double check if everything is grounded, I underestimated the depth of the box and it was hard to make the top look like the \"Akira style\" that was about to explode, so I talked about being in the studio with some friends, came up with a plan to show it in an angle. I did some quick prototyping with acrylic scrap and ended up with a good solution. It\'s kind of like the patch cable maze in the 60 s Moog synthesizer showing the birds nesting in the back. It\'s over, right? I used Neopixels in previous projects using MIDI and found out that MIDI needs a dedicated motherboard to do its job, so I run the \"original\" input from the 1st board using the 5 v power supply. I didn\'t write any fancy programs, just found a program from the strandtest sample sketch of the Adafruit library. To upload:1. Please make sure to download the midi _ controller. h library2. Select \"Arduino Leonardo\" from board type 3 \". Select borad from Port menu4. After compiling and uploading tests using the midi monitoring app. If everything seems to go as planned, then it\'s time to make some music! Because of its flexibility, I used Ableton Live in my project. It will still work if you use the garage belt, but the knob will have a fixed function, depending on what you program the MIDICC numbers in the sketch. Any questions? Leave them in the comments! Happy Making!