Inline code is probably faster than subroutine based code. I commented out all the HPWM subroutines and substituted in place of their calls the HPWM statements themselves.

My guess is that the SRF05's are blinking faster. That is very good.

I checked the SRF05 responses. They seem to be immediately after the one millisecond trigger pulse. PULSIN should not be timing out, but that is a vulnerability worth considering.

Ken