Iris not functioning quite right...

I had a hard landing and now the IRIS is not functioning as it was brand new.  What are my options for figuring out what is wrong? Do I need to call 3DR and get support? Is there a better way to start a self diagnosis?

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  • Seems like the re-cal on the compass did the trick.

    What kind of accuracy would I expect from the GPS? Did an RTL test this morning. About 4 metres out. Is that good? I'm sure it's acceptable if I needed but not sure if that is standard or not.

    Loiter mode was holding nice and steady.

    • iev had varying results out in the field, and actually msot of the difference seems to be due to the landscape.

      In a valley (hills on sides ) my gps and HDOP values are not as good. Literally moving 20m between 2 locations changed the valuse a lot and allowed a green gps ready lock.

      Once I had that the landing was within about 1 meter.

      Usually once 10m in the air gps is better and very stable.


  • Re-cal the compass and Iris RTL now, however, Loiter is still not 100%. She still doesn't like to hold altitude. GPS lock appears to be okay. More testing before I am 100% happy there though.

  • I too had a minor bingle on the week end. Flying in a footy field. Nothing else around. Slight cross wind. No other obstructions except for the goal posts. Iris drifted behind me and I took my eye off her. What do you think the chances are of Iris hitting the post? I couldn't believe it either. Seems like Iris has a massive magnet on board. Once I saw her slowly drifting towards the post, I hit the loiter switch but it was too late.

    Broke two props. Changed them all and went back today for a test flight. RTL did not work. Iris did however, ascend to what looked like the normal 15m, hovered for a moment, made her way back to her launch point. Stopped and hovered at 15m, but did not descend to land.

    Do I need to hook up to APM/Mission Planner and reconfigure?

    Hopefully that will do the trick.

    • imo, if you believe something could've been damaged in flight,  I would always initiate a flight in stabilize before attempting any other flight mode.  Check yaw/pitch/roll/thrust.  Check stability in a box flight.  Check recovery on a hard pitch/roll.  I would then move to alt hold to check barometer, then loiter for gps fix prior to returning to any autonomous flights or complex flight modes.

      Moving from stabilize->alt hold->loiter->mission/rtl will progressively step you up through the sensors and APM control logic and insure your sensors are all behaving.

      Also in Droid Planner, one time I noticed that Mavlink was reporting my drones was moving when it was sitting on the ground (not moving as a in slight GPS drift, but actually moving moving).  Clear view of sky, GPS lock.  That being said, that flight I did not try any GPS aided flight.  That spooked me out.  I would check on your GCS that the drone is where it says it is and has a good fixed lock before any GPS based flight modes too.

    • Good advice Francis. I have done a couple more test flights. Yaw, pitch, roll, forward and back all good. So manual flying is all good. Loiter mode I have noticed Iris slowly ascending and not holding altitude position. I have checked RTL again and Iris ascends, returns to a point above launch then descends a few feet, and holds altitude but does not continue down to land.

      I have re-calibrate ACC. Will re-cal the compass and check if any changes.

      Where can I check on APM Planner the values of the RTL landing height? Maybe that's been changed? Not sure. Iris just want to hang there though so not confident that that's the issue.

    • Cool so the accels/gyros are working which give you stable flight, I would assume an accel re-cal is not necessary if the stabilize feels ok.  Loiter drift may be GPS EMI or bad lock (but if it's an open sky, lock should't be an issue).

      As to how RTL works this link may help:

      Semi off-topic on GPS:

      There are some reports of some EMI due to the proximity of the Iris's GPS sensor to the rest of the electronics.  I plan to follow another DIYDrone member's modification and purchase a GPS Mast plus sensor case from 3DR so I can get the GPS out of the 3DR case to reduce EMI.  I did confirm with 3DR's customer support that they DO sell the GPS/Compass case separately but you have to email them to attach the item on the order (it is not on their storefront).  The cost they quoted is $5.

    • I think it would be best to recalibrate all your sensors after a hard landing or a crash... Especially the accels and mag.
    • What is "mag"?

    • I believe it refers to the "mag"netometer (compass).

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