AWOL:
IR != ultrasoundI've never had feedback problems with ultrasound.
oh my bad. I've worked with ultrasonic and IR for quite a while last year, got the wrong bookmark.
i was doing a maze solving robot last year, which uses ultrasound n IR. ultrasound pulses through the arena(2m square) and obstacles quite a bit. readings were sometimes jitterish.
had to do a take a bunch of readings, sort it and get its median