This is a picture of the breadboard ‘device’ I used to write the firmware against. The heart of it is a TeensyLC with pretty much everything else just wired in to it. The rotary encoder next to it is performing the function of the scroll wheel.

The joystick module can also be clicked in as a button, so the device got itself another button to map. I wanted the device to have event feedback mechanisms, so added a buzzer to provide programmable auditory feedback on events and made allowances for a vibrator module to be triggered for basic haptic feedback as well (not pictured).

I decided that a visual indicator of which preset was selected would be useful. The TeensyLC only has 128 bytes of emulated EEPROM to work with, so I limited myself to 3 presets and so used 3 LEDs. The device can be configured to disable them, or blink them as part of a mouse event as a visual feedback mechanism.

The hardware was tested on Linux, Windows 10 and MacOS.