PipKey v4 BLE MIDI Instrument

At long last, the PipKey is in a functional and satisfactory state! This 3D-printed, ESP32-based, battery-powered Bluetooth Low Energy MIDI instrument uses a combination of buttons, joysticks, and a spring-loaded rotating scissor lift mechanism to play music in a variety of interesting ways. Check out the following YouTube video for a quick demo!

https://youtube.com/shorts/QAQM8-zs1G0

You can also see the PipKey v4 working as a video game controller in the following demo:

https://youtube.com/shorts/br6Xhw2fNOw

In Version 4, I’ve leaned harder into the concertina/accordion inspiration started in Version 3, with a five-position rotatory position switch setup and a slide potentiometer for tracking the distance that the PipKey is pulled. The rotating positions can be used for actions like swapping between strings, octaves, or types of chords. The scissor lift assembly can be pulled to add vibrato effects to notes, as well as perform different notes in the same motion/style of an accordion/concertina/squeeze-box.

Since ESP32 microcontrollers have difficulty using both ESPNOW and BLE at the same time, two nRF24 controllers were required for wireless communication between both halves. The type of ESP32 that I’m using comes with a built-in Li-Po battery charger, which simplifies the circuitry a decent bit. The use of M3 binding screws (aka Chicago screws) as opposed to M5 screws in Version 3 allows for a denser amount of movement in the scissor lift.

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Printing, Assembly, & Coding Instructions:

I haven't included anything here because it would take a long time to write/photograph/document the full process and I’m unsure of any genuine interest in others recreating this project. Plus, I’m working full-time these days.

In order to maintain some form of protection over the project I've spent years progressively developing, I‘ve neglected to include the code that powers both halves of the device.

If you are genuinely interested in building one of your own, please reach out to me.

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Materials:
PLA/PETG
2x ESP32 WeMos LOLIN32 (Soldered with upward-facing Female Headers)
10x Choc Kalih Low-Profile Keys
2x PSP Joysticks
2x 1000mAh (Liter energybattery)
2x 2-pin JST Battery connector wires
2x Monochrome 128x32
2x Camera Straps ("SmallRig Camera Cage Wrist Strap”)
4x Switches (SS12F15-G5)
Various M2 & M3 Screws and Nuts
Various M3 Chicago Screws (For scissors lift assembly)
1x Spring (9.5x16mm Compression)
2x Spring (8x28.5+mm Extension)
1x 45mm Linear Slide Potentiometer
2x Microswitches
2x nRF24
2x8cm Protoboard
Female-to-Male Jumper Wires
Female Header Pins (Various Lengths)
Solid-core wire (Various colors)
2x 10uF Cap (for nRF24)
A bit of tape
Android Phone with Fluidsynth