I want to add a speedometer to my gokart. I expect to mount a magnet to the wheel or axle. I have an existing 15V meter used as my battery monitor, I want to use this and just switch between speedometer and battery monitor. I want a circuit to convert the wheel pulse to a proportional voltage. The kart would move three feet per revolution. I'll design it as a 45 mph F.S. speedometer.
1 mile = 5280 ft and 3 ft per wheel revolution so 1760 revolutions per mile. 30 mph will produce 880 pulses per minute or 14.67 hz. So, 14.67 hz should produce a 10 volt output to the meter. Well this seems like a pretty low frequency to work with, 10 mph would be a frequency of less than 5 hz. Can it be done, or do I need more pulses? I've never worked with the simple PICs, maybe it's time? Ok there's the info, what do you suggest? Thanks, Mike- posted
15 years ago