Maker and musician Oliver Hagen has designed a custom MIDI controller to address perceived usability issues on a Roland JD-Xi synthesizer — built around both a Raspberry Pi Zero 2 W single-board computer and an Arduino Nano-compatible microcontroller development board: the DivingBoard.
"[The DivingBoard is] a home-made MIDI controller aiming to solve the lack of parameter accessibility on the Roland JD-Xi synthesizer," its creator explains. "It differs from other solutions I've seen in that customizability and potential ease-of-use are greater, and general use with a range of synthesizers is possible, rather than just with the JD-Xi. It's a work in progress, currently existing as a functional prototype in regular use."
The problem, Hagen explains, is that the Roland JD-Xi is a powerful synthesizer with over 100 adjustable parameters to shape its sound — all accessed through just seven knobs on its front panel, requiring the user to dive into nested menus on a cramped display. DivingBoard, then, allows the parameters to be accessed more quickly — aiding musical spontaneity.
"The [Raspberry Pi] is connected to the synth via USB and exchanges MIDI messages with it," Hagen explains of the device's operation. "These messages tell the synth to adjust selected parameters to specific values, thereby exposing all the internal controls for easy manipulation. The kicker is that the eight physical controls on my controller can be assigned to different internal parameters arbitrarily, meaning that I can always have the exact controls I need under my fingers."
In addition to the Raspberry Pi Zero 2 W, a compact single-board computer, the DivingBoard uses an Arduino Nano-compatible microcontroller to read its inputs and drive the character-based display. "I [had] used a Raspberry Pi 3 [Model] B+ as the brain of this project because it's what I have on hand," Hagen writes of an earlier prototype. "I've tried the whole setup out with a [Raspberry] Pi Zero subbed in, and while it works, the latency is obvious."
More details on the DivingBoard are available on the project website, along with a software download; "I will try and put stuff on GitHub at some point," Hagen promises, "when I can find time to re-learn how GitHub works." Additional information is available in Hagen's Reddit post.