How to build a mapping
A setup is a file that tells a Roto-Control what every knob and button does for one particular piece of hardware, or one plugin.
Build it
Two ways in, depending on what you are controlling. Press MODE on the unit to choose.
MIDI mode
For a synth, or anything else with a MIDI socket. Works with no computer attached at all.
Press LEARN, pick the knob or button you want with the arrow keys, then turn the knob to dial in the MIDI channel and the CC number and press LEARN again to confirm. Set the minimum and maximum while you are there if the parameter does not use the full range.
Most manuals have a MIDI implementation chart in the back listing every parameter and its CC number. That chart is what you are transcribing.
You can skip the typing if your gear sends CC back. Press LEARN, pick the control, then move the knob on the gear itself, and Roto-Control reads the channel and CC straight off it.
Either way it saves into the setup you have selected. SEL switches between the 64 setups the unit holds, so park a work in progress somewhere you do not mind overwriting.
PLUGIN mode
For a plugin. The mapping comes out of Ableton Live rather than off a chart.
Press LEARN, touch the knob or button you want, then click or move the parameter in Live. Roto-Control takes the parameter's name from Live and puts it on the screen above the knob, so there is nothing to type. Press LEARN again to confirm.
Third-party plugins need one thing first, because Live does not expose their parameters until you ask it to. Unfold the device parameters, click Configure, and click the controls you want on the plugin's own window. Then right-click the device title bar and choose Save as Default Configuration, so it comes back the same way every time.
Assignments save themselves to the unit as you go.
Make it feel right
This is what people download somebody else's setup for.
- Detents. Set a knob to STEP and give it the number of positions the parameter actually has. A waveform selector with three positions should click three times, not sweep.
- Step names. Each detent can carry a label, so the screen reads SAW, PULSE, TRIANGLE as you turn it rather than 0, 42, 85.
- Indents. A single detent at twelve o'clock for anything that centers, like pan or detune.
- Color. Group by function. Filter one color, envelope another. It is how you find a knob without reading it.
Names are twelve characters. Shorter is usually clearer.
Export it
With the setup selected on the unit, choose File > Export in
ROTO-SETUP and save the .json file. That single file is everything: every
mapping, every color, every step label.
One exception. If a plugin comes in mono and stereo versions, as many do, the Roto treats them as two different plugins and a setup only loads on the one it was made on. Map both, export both, and zip the two files together to share them as one entry.
File > Export All saves every setup on your unit at once, which is also how you back the thing up.
Install someone else's
Select the slot you want to overwrite on the unit, then File > Import and choose the file. The app will warn you before it replaces what is in that slot, so park it somewhere empty if you are not sure.
Built something bigger?
Roto-Control publishes a full serial and SysEx API, and the source for its Ableton Live, Bitwig and Logic Pro integrations is on GitHub. If you have written a control surface script, a Max for Live device or a standalone tool, it belongs here alongside the setups.