I have used sonar in the past on quads to help maintain altitude during auto flights, loiter, and land mode. Some colleagues of mine want to try to use sonar not for altitude corrections but rather obstacle avoidance like the functionality of the optical flow sensor. I believe that the code in ArduCopter V3.0.1 does not support sonar in such an application, and that to do this it would require additions to the ArduCopter V3.0.1 firmware. My question is; is my line of thinking correct, and how involved would such changes to the APM's code would this require?
Thanks in advance,