Measure frequency 

Hi everyone
I want to measure the frequency of a square signal (Beaglebone). Is it possible to do this using the adafruit library (400 kHz)? I tried using PRU but didn't get the accuracy (https://github.com/SuperEjik/frequency-measurement-with-PRU-BeagleBone-CYCLE-register-/blob/main/cycle.pru0.c).