Different LGR Behaviors Between Two Quads

ArduCopter
1

As some of you may know, I have built two Tarot 650 Sport Quads:

Both Quads
Both Quads1920×1440 767 KB

The larger one on the left, which I will call Tarot 1, works fine with respect to its landing gear - they retract when ascending and stay that way until descending to land, they extend. However, the Tarot quad on the right, Tarot 2, behaves differently; the landing gear remains extended after takeoff and during a waypoint mission, and when descending to land, they retract. I tried toggling the landing gear switch in an effort to extend them before landing but was unsuccessful. Before going further, let me state that both aircraft use a Holybro 6C flight controller.

Previously, I compared LGR - specific parameters between the two and found a discrepancy in LGY_DEPLY_PIN values; Tarot 1 had the value 54, so I set the same value for Tarot 2. But this had no effect. I wrote out the parameters from both aircraft and compared. I did find some discrepancies in some other parameters that I need to fix that are unrelated to this problem, but for LGR - specif parms they are identical:

LGR Parms
LGR Parms1599×2068 289 KB

At this point I am at a loss as to what the problem is. Can anyone offer any suggestions?

2

Most of those cheaper landing gear systems are simple DC motors with limit switches and reversing logic in the controllers. Do you have the power polarity reversed?

You can also simply try reversing LGR_DEPLOY_POL (wouldn’t be the first time QC on such parts was a little suspect, resulting in reversed polarity under the hood).

1 Like
3

That thought did occur to me but I guess that I expected the landing gear to work the same way from the same manufacturer. At any rate, I will try reversing that value and see what happens. Will let you know.

Thanks!

4

The experiment failed. reversing the LGR_DEPLY_POL value did not work, so I’ve decided to bypass the fc altogether and manually control the landing gear.

5

Why you don’t show log files from TAROT1 and 2. These logs will show if the FC tries to retract or deploy the landing gear.

2 Likes