As the wheel slows down the microcontroller detects that and changes the led pattern at a slower rate. But at a slow enough rotation your eyes start seeing each

As the wheel slows down the microcontroller detects that and changes the led pattern at a slower rate. But at a slow enough rotation your eyes start seeing each individual led arm rather than the whole image. When the wheel stops I have it detect that and stop shining the LED's until it starts spinning again.