I have a speedometer for a bike that uses a reed switch and magnet to count rotations per sound and calculate speed. My problem is the wheel on the bike is too small for the speedometer to calculate (to many rotations per second). I’m tiring to build a circuit that will output every other magnetic latch rotation to the speedo. Half the rotations per second. I know how to do this with 2 relays, but I don’t want to waste the battery power to drive them every time I ride. I would prefer to do the process with an IC. Does anyone have any ideas?