Landing Gear activates on boot

Hi all. I’m a newly registered user here. been lurking for a while as I build my 680 Hexa. Thanks too all for sharing your passion for the hobby, and valuable insights.

As the topic states, my landing gear gets activated on boot up. Ive tried reversing the PWMs, reversing the channel. All combinations of what to connect first etc… No go.
The gear works beautifully manually, even auto deploys on landing and RTL. The Wiki says that there is logic to prevent boot activation from happening. Ok…Regardless of gear position when I boot. the gear gets triggered.
If I boot gear up, they go down. If I boot gear down (normal) they go up. Any ideas???

After a bit of tinkering around with all my settings, I figured it out. So for all who may experience this, here’s what I did.
I first tried reversing the channel on my TX. It just work in reverse but Pix did the same thing.
Switched it back, then, reversed CH7 options in the param list. Same thing. Just worked in reversed but Pix still retracted on boot.
So, after much gnashing of teeth and head scratching, I reversed the LGR_SERVO_RTRACT and LGR_SERVO_DEPLOY PWM numbers and lo and behold…IT WORKS!!!

Thanks all…

I didnt want to bore everyone with my bragging on my rig but here is what I’m working with…
HK 680UC Frame, Turnigy 640kv motors, Pixhawk with latest greatest beta FW, Spider Ztw 30A Opto with SimonK Oneshot125 ESCs, Retract Landing Gear (obviously) and some cool lights. I’ll post a pic if anyone is intersted…

Thanks again

I’m going to let RobL answer this one 'cuz he was the developer of the landing gear feature.


I have just installed v3.3 and having issues configuring the landing gear between the radio and the Pixhawk FC. The FC will actuate the landing gear by toggling the servo on the Mission Planner, Flight Data screen but I cannot get the CH 8 switch to coordinate. Can you offer some of your experience with this matter?

Hi Wstewart
I didn’t have many issues getting it to work. Just getting to work in the proper direction.
I used channel 7 and configured it for Landing gear. Make sure you have the proper voltage and ground for your gear (Typically 5v) on the Pixhawks power rail. This will power the landing gear. See my previous post about the PWMs i changed to reverse direction…
Make sure your gear is plugged into the correct CH on the Pixhawk. That should get you going.

Good luck…

wstewart, can you please go into detail on the problem you are having?

Is it just that the Ch8 switch isn’t working? Have you set Ch8 Option to Landing Gear?