Introduction - If you have any usage issues, please Google them yourself
Use Timer0 in 32-bit periodic mode to request interrupts at a
particular period.
oscilloscope or LED connected to PF3-1 for period measurement
When using the color wheel, the blue LED on PF2 is on for four
consecutive interrupts then off for four consecutive interrupts.
Blue is off for: dark, red, yellow, green
Blue is on for: light blue, blue, purple, white
Therefore, the frequency of the pulse measured on PF2 is 1/8 of
the frequency of the Timer0A interrupts.