Devices Override format description

Device Overrides are a specialized extension mechanism that allows users to customize the assignment of MIDI ports and channels to devices defined within a preset. While presets serve as the core structure for mapping and controlling MIDI devices, including layout, controls, and MIDI messages. Device Overrides provide a way to alter the default definitions of those devices without modifying the original preset.

Relationship to Presets

Each preset in Electra One can reference between one and up to 32 device definitions. These devices represent standardized descriptions of external MIDI gear or software. A device definition typically includes information such as the MIDI port and channel where the device is connected, its name, and optionally, instructions on how to request and parse data exchanged between Electra One and the device.

Since different users may have their MIDI devices connected to different ports or channels, they often need to edit the preset to make the necessary adjustments. Device Overrides offer a solution by allowing users to apply these changes without modifying the preset itself.

A Device Overrides JSON file provides an alternative version of MIDI device definitions, specifically for MIDI port, channel, and device name. If this file is present in the preset slot alongside the preset, Electra One will use the device information from the Device Overrides file instead of the one embedded in the preset.

Adjusting the Devices

When a preset is loaded into a preset slot, Device Overrides can be added in two ways:

• via the Devices screen in the main Menu on the Electra One device
• by uploading a Device Overrides JSON file via SysEx

Lifecycle

Device Overrides are scoped to a specific preset slot on the Electra One. Their lifecycle is tightly coupled with the preset currently loaded in that slot:

• When a new preset is loaded into the slot, any existing Device Overrides file stored there is removed.
• After the new preset is loaded, the device definitions from the preset itself are used, unless a new Device Overrides file is applied.
• Any adjustment made via Devices screen in the main Menu on the controller will create or replace the Device Overrides JSON file in the current preset slot.
• Uploading a Device Overrides JSON file via SysEx will also create or replace the file in the preset slot.

If a preset with the same projectId is uploaded to the preset slot, the existing Device Overrides file will be retained. However, uploading a preset with a different projectId will cause the existing Device Overrides file to be removed.

Issuing a SysEx command to remove a preset or clear a preset slot will also remove the Device Overrides file, along with any other associated files stored in that slot.

Devices Override JSON format

JSON schema

The JSON schema of the Electra One Device Overrides file is available at GitHub.

Top level objects

The perforance has three top-level elements.

{
  "version": 1,
  "devices": [
  ]
}

version

Provides information about the version of the device override file. Electra One controller uses version information to distinguish between various device overrides file formats. Note, this document describes version 1.

example

"version":1

devices

An array of devices. A device is a hardware MIDI device or software device (application, VST/AU plugin) connected to the Electra One.

• mandatory
• array

example:

"devices": [
   {
      "id": 1,
      "name": "My MKS-50",
      "port": 1,
      "channel": 1
   },
   {
      "id": 2,
      "name": "BeatFX plugin",
      "port": 2,
      "channel": 1
   }
]

Device

A device refers to a MIDI hardware or software instrument connected to one of Electra's MIDI ports. This could be a hardware synthesizer connected via a port onMIDI IO interface, a hardware sequencer connected to Electra's USB host interface, or a software plugin communicating through Electra's USB device port. Electra supports up to 32 simultaneously connected devices.

When working with Electra, you must define your connected devices explicitly - you do not send or receive MIDI messages directly to a port and channel, unless you are using low-level Lua API calls. This abstraction ensures consistent device handling and simplifies preset and control configuration.

example:

{
   "id": 1,
   "name": "Generic MIDI",
   "port": 1,
   "channel": 1
}

id

A unique identifier of the device. The identifier is used in other objects to refer to a particular device.

• mandatory
• numeric
• min = 1
• max = 16

name

A user-defined name of the device. The name makes it easier for users to remember and identify devices.

• mandatory
• string
• minLength = 0
• maxLength = 20

port

A port number represents a MIDI bus inside the Electra One. Port 1 interconnects MIDI IO Port 1, USB Host Port 1, and USB Device Port 1. Similarly, Port 2 interconnects MIDI I/O Port 2, USB Host Port 2, and USB Device Port 2.

• mandatory
• numeric
• min = 1
• max = 2

channel

A MIDI channel where the device transmits the MIDI messages.

• mandatory
• numeric
• min = 1
• max = 16