KernTroller

The KernTroller is a customizable keyboard controller with pressure sensitive capacitive touch pads, based on the Adafruit Trinket M0 board, and is programmable with CircuitPython!

The default configuation has you ready to kern in Type Supply's MetricsMachine but its functionality is easy to customize by changing a few lines of Python code. Essentially, your computer sees it as a keyboard, and the mapping of button presses to keyboard keystrokes is all outlined in a Python script running on the device!

The capacitive touch pads can sense a range of values depending on how firmly you press down each the “button” pad, and can then trigger different keyboard shortcuts accordingly (i.e. the keyboard command for a 1 unit kern adjustment with a small press, 5 or 10 units with a firm press).

The KernTroller was also designed to use a minimal set of components, with the goal of making it relatively easy to build.

What's this?

Back at RoboThon 2015 I presented some of my thoughts and experiments with making custom controllers for type design. I've noticed that other creative industries have their own cheap comodity input devices (USB fader banks for musicians, 3D ”navigator” devices for industrial designers, etc.), but I wonder what kind of devices a type designer needs. At that time CJ Dunn observed that MetricsMachine looks like it's practically designed to be used with a video game controller — USB video game controllers can be found relatively cheaply, and it turns out to actually be a really nice way to interact with a repetitive task that only needs 6 keys to perform.

An excellent way to get started prototyping new hardware is to use the Arduino development boards. It's easy to get started with them, but as a Python programmer it meant a new language to learn. Jump forward to August of 2017 and Adafruit released the Trinket M0 which can function the same way as an Arduino does, but even better, it comes by default set up to be programmed with CircuitPython! For $9 there's really no better way for a Python developer to get started developing new hardware, that is, unless if you wanted to start with the Circuit Playground Express which already has a few buttons, LEDs and sensors built in.

I've slowly kept on with all of this stuff on the side, so three years later, at RoboThon 2018, I better have something to show for it!

Why make one when you can just buy a cheap controller?

Now you’re trolling me!

The Hardware

The KernTroller hardware was designed with the hope that it's easy to build, and consists of one custom PCB, the Adafruit Trinket M0 dev board, and a couple of buttons. An overview of the hardware and a build guide can be found in the Hardware directory of this repo.

The Software

The best part — it's easy to customize how the KernTroller functions by editing a few lines of Python code! The Trinket M0 simply mounts as a drive on your computer, giving you direct access to the code living within. Sample presets and an overview of how the software works can be found in the Software directory of this repo.

Let me know what you think!

Let me know if you have any questions, or if you made one yourself! I'm also available to give a small workshop on an introduction to electronics and Python by building and programming the KernTroller, so get in touch!