Hi all. I am trying to measure the RPM of a motor and have a few questions. The motor is turning slowly(about 132RPM after gearing). There is an "optical encoder" on the shaft that gives me 8 pulses / rev.This gives me a pulse every
56ms or so. How can I calculate the RPM of the motor WITHOUT using floating point routines and in a fairly fast time. I could wait 1 second , count the number of pulses / 8 * 60 to get RPM , but this takes far to long(1s) :0( I can measure fewer pulses , but the time is still to long. I could measure the period of 1 pulse , invert / 8 * 60 to give RPM. This is much quicker , but involves floating point routines. I can gate a timer in the micro with the pulses from the encoder to give me a count in the micro , but this will also involve floating point routines to get back to rpm. Is there a simple solution to this problem(probably) and I've missed the boat completely or am I stuck with the options I have described:0( Cheers Rob- posted
17 years ago