"Well, the APM doesn't have enough time waiting for feedback from the HC-SR04, yes it's the matter of timing and interupt. To make thing works as the video, it require another brain or controller to do the triggering and waiting for echo. The…"

"I finally managed to download the .bin log from my APM, while i use sdlog2_dump it ended with KeyError :180, any clue about this?"

"Can we do something with the telemetry log beside exporting to GPX? the log limitation on the APM makes it hard to store a long multiple flight. I just back home from several flight and got some of the log already been overwriten."