Introduction to Lua

Why Lua

Lua is a lightweight programming language designed to be embedded inside other applications. It was created in 1993 in Brazil, and from the beginning its purpose was clear: be small, fast, portable, and easy to integrate with software written in C or C++.

Because of these qualities, Lua became widely used in the gaming industry, where it allows developers to script behavior, user interfaces, and game logic without recompiling the entire engine. It has also found a strong place in music technology, where flexibility and real-time control are essential. Applications and platforms such as Renoise, REAPER, Ardour, and hardware environments like monome norns use Lua to provide users with powerful customization options.

Electra One follows the same philosophy. Its firmware is written in C and C++, which are compiled languages. Compiled code is translated into machine instructions before it runs, providing maximum performance and direct hardware control. The firmware .srec file you download when updating your Electra One is a compiled image of that C/C++ application. If you had to write your scripts in C++ instead of Lua, the entire process would become slow and cumbersome, requiring recompilation and deep system knowledge.

Lua, by contrast, is an interpreted language. This means your scripts are executed by a Lua interpreter running inside the firmware. You do not need to compile anything. You write a script as part of your Electra One project, upload it to the controller, and it runs immediately. This makes experimentation fast, safe, and accessible, while the performance critical parts remain handled by the compiled firmware underneath.

Electra One Lua Editor

In principle, Lua scripts for the Electra One controller, and even the JSON preset files, can be written in any text editor. There is nothing technically preventing you from doing so. The more complicated part is transferring those files to the controller.

To upload a script manually, it must be converted into SysEx messages and sent over MIDI. While this is entirely possible, it requires additional tools and a solid understanding of the data format. It is not the most convenient way to work, especially during development.

For the remainder of this book, we will use the Electra One web editor. This is the official editor maintained by Electra One, developed and maintained by Zdenek and myself. The editor not only simplifies transferring files to the controller, but also provides a fully integrated environment for developing presets and Lua scripts.