One of our more amusing click boards goes yellow, with Rotary Y click.
A fourth color? Y not? When fully lit, these 16 LEDs radiate from the 15-step rotary encoder like sun rays on childrens' drawings.
Needless to say, it works the same as with the red, green and blue versions. It's a knob you can spin around continuously, each full circle comprising 15 steps that go click, click, click. The output consists of A and B signals which are out of phase to each other.
You can also push down on the knob, which will send an interrupt to the target board MCU.
The LEDs are controlled separately, through the SPI interface.