Best way to measure period between pulses? Counters and FPGA

[Alan Anderson]

Originally Posted by saikiranra

Also, teams who have done this before, how accurate is finding the RPM using an optical sensor compared to using an encoder?

The typical quadrature encoders used on FRC robotis are optical sensors. The accuracy is going to be the same, assuming the sensor detects all the marks it's looking for. The precision will be a function of the number of "ticks" per revolution and the consistency of the spacing of the light and dark marks. In general, more marks seen going by in a given time gives better precision.