Pixhawk safety switch difficult to arm

I have a Pixhawk on my quad with 3.3.3 firnware. I understand that to arm the Pixhawk, the safety switch should be pressed and held for 2 or 3 seconds for it to arm the unit. I am finding that very occasionally it will do this if done a soon as GPS is locked. However, I find that most times it will not arm; sometimes it could take several minutes of trying before it finally gives in and arms. I’ve not been able to find any parameters for setting the switch behaviour, expect for disabling it; I don’t wish to do that.

Does anyone know what is happening please?

You’ll need to connect a GCS to see the reason why http://ardupilot.org/copter/docs/prearm_safety_check.html#

You can use a tablet based GCS for convienece

Bill, I don’t think I quite explained the problem clearly enough. The Pixhawk appears to have passed the pre-arm safety checks, as the the LED flashes regular green suggesting that it is ready to be armed. The problem lies with the safety switch not responding to a 2-3 sec press. Very occasionally it may do so first time, but mostly it won’t respond for several minutes; all the while the LED is flashing green and no spoken system problems. The GCS gives no indication of any problems. Once I am able to press and get it into a ready state, the GCS will tell me it is armed when holding the throttle down and right. Then the system works normally. Phil

Is the switch OK? I’ve never seen this!

Using Rover, Plane and Copter without any delay of this kind.


Anders, I’ve tested the switch with my test meter; it is OK. So I’m wondering if it’s a connector problem. I’ll look into that now and report back.

I think I may have solved it. The switch connector wasn’t making a good connection, after fiddling with it I am now able to put the Pixhawk into arm mode more reliably. I still have to try 2 or 3 times, but it is working mostly. Perhaps I should replace the switch; annoying though, as this is brand new gear and not yet flown. I’m now waiting for the batteries to come, then I can test it - it will be a nervous episode, hoping I have the setup right!

Had the first flights today; very successful! Very happy to say that the safety switch behaved properly too. So I think I can close this now. Thanks for your input.