Quote:
Originally Posted by apalrd
We had a 4-line disc with very uneven dark/light spacing and not terribly accurate angular spacing, but if we setup the counter to average 12 samples then any phase error between the lines would cancel out and we got a really nice clean signal.
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With 4 pulses per rev, you need only 4-sample averaging to completely cancel out the jitter due to the inaccuracy of the pulse spacing.
Increasing it to 12 helps to further cancel out the jitter due to the 6.5us resolution due to the rate at which the FPGA looks for pulses.