I am working on a project that needs to read 6 water flow sensors that output one pulse for every .1/cubic foot of water. The maximum pulse rate would be about 13 pulses per minute. I don't need to know the length or frequency of the pulses, just count them. As the sensor revolves about 1/3 of the time the output is high, 2/3 it is low, so quite likely one or more sensors will be inactive and remain high at any given time.
I can think of a couple of ways to do this but my solutions are kludgy, I'm quite sure there is an elegant and simple solution that is beyond my abilities using the counters or some such. Any tips towards a simple scheme to read these sensors?