Why this project?
After successfully creating a MIDI-Mixer during one of my advanced prototyping classes and experiencing the joy of performing with it, I found myself captivated by the idea of delving deeper into the realm of MIDI protocols. Eager to push my creative and innovative boundaries, I set out to challenge myself: Could I design and construct a fully functional Bluetooth-enabled MIDI device capable of seamlessly connecting to my iPad in under four hours?

How it works
MI-DIY harnesses the power of an ESP32 dev board as its central processor, equipped with seven analog and three digital inputs. Comprising three mappable potentiometers, three push buttons, and a joystick controller, its components seamlessly interface with the code, translating their inputs into MIDI commands. These commands are then wirelessly transmitted via Bluetooth to the paired device. To fully utilize MI-DIY's capabilities, users require a MIDI app on their device, which will interpret the Bluetooth signals and translate them into actionable commands for their chosen synth applications.

Why was this meaningful?

This project was meaningful to me because it allowed me to stretch my creative muscles and find a practical solution that eliminated the necessity of purchasing a MIDI device. It provided a valuable opportunity for personal growth, enabling me to explore new concepts in electronics and programming. Additionally, working on this project offered a welcome reprieve from the structured demands of my college coursework, allowing me to immerse myself in a hands-on, self-directed endeavor.

The process
I began the process by creating a box using MakerCase before exporting the design file as a .dxf and importing it into Fusion360 for further modifications. I added a slant the top and an added cover with inserts for the various analog and digital inputs. Once the design was completed, the file was sent to the laser-cutter and cut out of plywood.  

Once the pieces were secured, I began to secure the components to their necessary places on the top board and began soldering the connections to the ESP32 dev board. I used a trick that I had seen in a YouTube video for creating a common ground (GND) and positive (VCC) terminal by using copper tape as a common strip for each line. Once the wiring was finished, the box was closed using 3M nuts and bolts in the appropriate spots and the coding began. 

I used the Arduino IDE to create the code with the MIDI-BLE library as the foundation for Bluetooth communication. Once the code was finished, I uploaded it to the on board ESP32 and connected it to my iPad using an app called Conji, which is designed to help wireless MIDI devices communicate with iOS compatible synth applications. The app I used as a synth was a free packet called Synth One. Each input on the device is individually mappable however for my purposes, I mapped the top three potentiometers to control volume, semitones, and detune followed by the next three controlling frequency, resonance, and glide. The joystick controlled pitch with vertical motions and modulation with horizontal inputs. The three push buttons engaged preset notes on a set loop.

Final shots
Below are a few more shots of the final project in good lighting