Overview
This is to document the limitations of the Beaglebone black. One caveat is that Adafruit Python BBIO Library was used. Any overhead from this may limit the behavior of the BBB. This will be consistently updated with new material.
Table of Contents
- PWM
PWM
PWM module available on the BBB is from the sitara core (AM 3359). It is a ehrPWM which according to documentation uses at max a 200Mhz reference clock. However, this only tells me the absolute maximum the PWM can run at. To investigate the actual performance limits, I ran an experiment where the frequency of the PWM module was varied with a 50% Duty Cycle.
Theoretically, we would want the square pulse where it would settle to the final value, but this may not matter we it was used to drive a switch.
Results
Safe frequencies to use --> <9MHz: For audio purposes, this is much more than needed.
Next Steps:
- Determine if there are duty cycle limitations to the PWM at higher frequencies.
- Determine maximum frequency where square wave is majorly affected by the ringing and wont settle to a final value.