How to correctly power-on a Pixhawk?

Hi all,

I’m new to multicopter and APM::Copter. I had several successful flights with my quad (Stabilize, AltHold, PosHold, Drift, Auto, AutoTune, etc) but the last one ended in a bad crash. I’m a bit concerned about how to correctly and safely power-on my Pixhawk.

I’ve read that you need to power it on while it is level on a stable ground. I’ve also read that some people wait at least 3 minutes before arming (mainly I guess to get a stable GPS signal).

I did some tests with the Pixhawk only connected to USB and it seems that if I power it on while on the side and in my hands, it waits (red-blue leds flashing longer) to be put in a stable position. Afterwards, the HUD in APM Planner 2 seems to be responding perfectly as expected. Also I’m wondering if temperature changes when take the drone outdoor could have some influence.

So my questions are:

[ul][li]How do you power-on your Pixhawk-powered copters? Always on flat ground? In any positions and then put it quickly on level ground?[/li]
[li]Do you wait some time after powering it on and before arming? If yes, only because of GPS or for some other reasons?[/li][/ul]

Thank you.

It depends on the version you are running. Old versions had an issue with being moved after power is applied. That was later corrected.

There is a new version coming out in a few weeks that will change the way it powers up. It will have more lights and tones to indicate condition.

The big thing about waiting is to get a good GPS signal as it can take sometime to get a good locked on signal that points to the correct GPS location. So waiting for a low HDOP can help pin point your location so that when it does an RTL it actually flies to that point.

This can also effect geo fencing if you have it turned on. It uses this information to determine how far from home it is to determine when the fence has been breached.

That being said I usually only wait till I have a green flashing light and take off knowing that home maybe several meters off it current position.


Thank you Mike.

So has I understand you in 3.2.1, powering my Pixhawk while holding it and putting it on the ground afterwards shouldn’t be an issue. Good.

I also already noticed once the effect of arming without having a stable GPS signal. The landing target was off by some meters when I triggered RTL.