Stephen Coyle is a composer who also writes iOS apps. Naturally, he uses his talents to write music for these applications, and needed a way to get sound from his musical keyboard to his iPad and computer. While a USB-MIDI adapter does the job, this presents a few difficulties, including the fact that he couldn’t use this setup with his laptop undocked without some rearranging of wires, and connecting it to his iPad involved the same sort of cable rearrangement, plus another dongle.
To resolve this issue, he turned to a Raspberry Pi running a software package called Ravelox, which allows the Pi to take in MIDI signals form the keyboard, and transmit them wirelessly via WiFi. This means that he no longer has to worry about physical connections when he needs to move his laptop, and can also interface with his iPad without issue.
The Pi and associated wiring are nicely hidden in a channel on the underside of the keyboard, allowing him to install and hide the hardware without any permanent changes. The mod even came with an added benefit in that Coyle could finally replace his aging power supply with a more power-efficient model. It takes care of both the keyboard and the Raspberry Pi via a switching regulator that he wired in.