[alin23]

An ESP32 would be a much better choice for analog MIDI: https://github.com/max22-/ESP32-BLE-MIDI

You could hook the wires from a MIDI cable to some ESP32 pins, read the MIDI messages and send them instantly through BLE to an iPad/MacBook.

An ESP32 board has the advantage of booting instantly, can be powered from a battery for a lot more time, can't cause SD card corruption, and is less susceptible to delays caused by the kernel scheduler.

I usually choose the Lolin32 Lite because it's very compact and has a built-in Lithium battery connector which can also charge the battery: https://diyprojects.io/wemos-lolin32-lite-compact-revision-l...