> 1)      Average LED current

Which should not be under-estimated. Pulsing LEDs at high
speed can cause instantaneous currents of amps - not good
for a PIC pin. Better for a more suitable device to take that
sort of punishment. Although the LEDs are receiving these
pulses, we don't (and shouldn't) see them. It's our persistence
of vision that makes them appear to have an even, average
brightness and the display as whole to move smoothly

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