Key concepts

In ReaLearn, the term control typically refers to the process of triggering or adjusting something in REAPER, such as executing an action or modifying an FX parameter.

In ReaLearn, the term feedback refers to controlling LEDs, motorized faders, or displays on your device in response to events in REAPER, such as a track volume change.

A controller is the device you use to control REAPER. It is usually a hardware device, such as a MIDI keyboard or control surface, but it can also be software, like an OSC app.

A control element is any component you can use to control something. In most cases, it’s a physical part of your hardware Controller.

Examples include knobs, encoders, faders, buttons, keys, pads, pitch wheels and acceleration sensors.

A control element interaction is the act of using a Control element.

Typically, each control element has one primary interaction type:

However, some control elements allow multiple interactions:

In this reference, Control element often implies Control element interaction, as they are usually synonymous.

A feedback element is any part of your Controller that can indicate or display information.

Examples includes LEDs, motor faders and displays.

Very frequently, control elements and feedback elements are combined:

For this reason, this reference sometimes uses Control element to refer to both the Control element and the corresponding Feedback element.

To enable control, ReaLearn needs to respond to events from your Controller. It achieves this by listening to events from an input port, which can be a MIDI device port, an OSC port or your computer keyboard.

You can change the input port using the Input menu.

To send Feedback back to your Controller, ReaLearn transmits instructions through an output port, which can be a MIDI device port or an OSC port.

You can change the output port using the Output menu.

A ReaLearn instance is the same as a Helgobox instance.

Each ReaLearn Instance contains at least one unit, known as the main unit, but it can also contain an arbitrary number of additional units.

Units function like "mini instances" within a single ReaLearn Instance, allowing that instance to manage multiple controllers simultaneously. Each unit has its own Input port, Output port, Controller compartment, Main compartment, Controller preset, Main preset, and more.

Each unit consists of two compartments. A compartment is a self-contained list of mappings that can be saved as an independent preset. The two compartments in each unit are:

Each compartment contains a list of mappings.

A mapping connects a Control element and/or Feedback element on your Controller with an action or parameter in REAPER.

Each mapping consists of Source, Glue and Target.

A source is the part of a Mapping that typically describes a Control element and/or Feedback element on the Controller. More generally, it can be anything that emits control values.

Examples: MIDI source, OSC source

A glue is the part of a Mapping that sits between Source and Target, filtering and transforming Control and Feedback streams.

This is a very powerful feature of ReaLearn, as can be seen by looking at the Glue signal flow.

A target is the part of the Mapping that describes the thing which should be controlled and/or provides feedback data.

Examples: Track volume, cursor position, REAPER action

This section wouldn’t be complete without mentioning the concept that inspired ReaLearn’s name: Learning. Learning simply means that you press a Learn button instead of performing manual setup, saving you valuable time!

In ReaLearn, you can learn sources and targets.