I updated the fw at the same link. It’s a little smaller, so not sure if I did something wrong. Not convinced what I have done will work, but now critical that you boot with the TX off.
Well I it worked. 
Thank you so much for all your help
You mean it worked, worked - or just boots?
It boots and it works. The tone when I device is disconnected is heard (RC not connected I imagine) and then when I started the TX then tone that a device is connected is heard. I can see all the 6 channels in the radio calibration.
Awesome! Ok, so I will do you a build without debug that you can be getting on with. I need to consult @tridge about whether we can do any better on the initialization front as it is a bit involved.
Great! So the TX needs to be off when booting the Pixhawk. I just verify that.
Andy, one interesting behavior of the build is that the disconnected tone seems to be looping after boot up until I connect (turn on the TX). Is that by designed?
Thank you
It’s not by design, but I can see how it might happen. Basically the RC type is not locked until it receives data - but data will not be be received until the TX is on. But bootstrap needs to happen without data. I need to figure out if we can have some kind of grace period while in bootstrap mode. Does failsafe work? i.e. if you switch off the receiver is the RC signal lost and stays lost (you don’t want the looping behaviour if possible)
Can you send me the debug for when you boot but before the tx is on? I want to see what it sends back (if anything)
This is a better non-debug version: https://www.dropbox.com/s/8emqgz0odjvtz7y/arducopter.apj?dl=0
please see if it still works. Thanks
It still works but it has the loop while the TX is not turn on. I think I made the mistake to update MP and now my controls are swap (thro, pitch, roll) yaw remained the same
No that’s me - the fix included swapping the channel order to match ardupilot expectations. You should no longer have to use RCMAP to get things how AP is expecting.
So it still works - great!
Does it work if you switch on the TX first before booting?
If you switch the TX on it doesn’t work.
Ok thanks - I’ll talk to tridge about whether this is possible at all.
I just did another re-booting and the loop is gone. Weird
I expect the loop. Basically it bootstraps ok but then because its not getting any data after 200ms it decides its still searching and sets the radio failsafe, because it bootstrapped ok the update method gets called which it makes it bootstrap again and round you go.
I found a couple of issues, which I think I have fixed - but want to make sure I have not broken you. Would you be able to give it another go?
Sure Andy. Thank You.
Andy, everything appears to work properly. I have a couple of issues but I don’t think is related to the firmware. 1) I have a ublox m8n GPS/Compass combo and the compass stopped working 2) for some reason I cannot arm the motors with the controller but I can with MP.
I’ll create another post if I can’t resolve the issues. I have calibrated properly the ESC and the Radio so I’m reading the troubleshooting section for such an issue.
Thank you
I guess check the channel ranges on your transmitter. I guess it’s possible you can’t arm if yaw is not going high enough or the channels are mixed up. A recalibration may solve this.
But great to know it’s still working. I will try flying with this today to see if I encounter any further issues.