Use an AS5600 magnetic angle sensor and a couple of switches to make random hardware knobs.

Typically with something like a Pimoroni Tiny 2350 with a Qwiic connector for i2c, and 1-4 GPIOs connected to switches (with the other side of the switch just connected to ground).

Or take this as a base and do something else.

NOTE! This particular setup assumes that you have a WS2812 RGB LED, and has a PIO program to send it data. That is somewhat common (eg Waveshare RP2350 Zero), but it is by no means universal. Some have just a single LED controlled by a single GPIO.

The Pimoroni Tiny has a RGB LED, but it's not the WS2812 smart LED: it has a "dumb" RGB LED with RGB programmed through three separate GPIOs individually (GPIO 18/19/20 for RGB respectively - typically using PWM to set the level of each color).

You don't need a LED for any of this, but it's nice to have for visual debugging, so just be aware that

All the other GPIO assignments are also random based on board (eg the Pimoroni board puts i2c0 on GPIO20/21, while the included board file is set up for the more normal GPIO4/5).

So don't expect to just "build and use as-is". Also don't expect anything polished. This is one of my early rp2354 project trials with minimal updates to bring it up to snuff again.