__Propeller Clock Timing Theory__In order to output at the same location consistently as is required to create the POV 'optical illusion' we must have perfect timing. Luckily, the PIC 18F252 has a digital timer that will let us do just that!

__Calculating Each Timing Step__Since we know the FAN's RPM, we can use some math to find out the delay between 1° intervals for LED outputs as the fan turns the propeller clock around the circle. The calculations seen above use our known RPM value to find out how long it takes to travel from 1° to 2°. This value:

**43.85uS**is how often the timer should be set to interrupt and update the output leds. If there are led outputs at every 43.85uS then there should be 360 specific locations where the LEDs can be seen when the fan is turning full speed.