I have a brand new sonar (order 20017)connected to my APM2 via a servo cable.
The sonar always gives 22-23 cm regardless of altitude and this sends my quad into orbit if i switch to alt_hold.
I can make the sonar give proper reading for a minute or two if i tap it gently or holding/fiddling with it.
What to do?
Same Issue here with APM1 and XL-EZ0 though I haven't tried tapping. Sounds like bad/loose soldering perhaps?
For me it is between 21 and 25. I can move around at that distance between 21 and 25 and get it to change. anything closer than 21 is read as 21. Anything above 25 is read as 25. I can hold my hand in between and hold them at 23 or 24. Pretty darn frustrating.
Thanks for your reply. I contacted 3DR support with my problem and they gave me an RMA number, I sent it back for about two weeks ago. Havn't heard anything yet but they were really helpful.
I installed one recently and it works great. Testing inside wasn't giving good readings though - something like Romp's results. 21cm is about the minimum it reads anyway, but I wasn't getting very high readings.
However, out in clear air, I flew across a tennis court at about 4m up, and it reacted to the top of the net! The sensor is extremely sensistive. You want to make sure the sensor is in the clear of everything nearby (including wires) to at least probably +/- 60 degrees if not +/- 90.
Also make sure you use shielded wiring (discussed elsewhere in this forum) and filter the power and output as per MaxBotix's FAQ.