Use either CD4510 or 4516 UP/DOWN counters.
I think you need to get both signals cut at a particular time in either direction to perform an UP or DOWN count. So it depends on the distance between the two signals and of course the size of the person enters. Do not use a laser beam.
I think you need to get both signals cut at a particular time in either direction to perform an UP or DOWN count. So it depends on the distance between the two signals and of course the size of the person enters. Do not use a laser beam.