I am a junior RC aficionado, have been going into drone´s world for last two years.
I have performed my own quadcopter with Pixhawk as flight controller. In maiden flight, when drone was armed and I tried to take it off, motors went crazy and drone just rolled on ground before crash check failsafe activated.
At the moment of the accident, dron was also equipped with a Raspberry Pi3 and FPV system (camera+transmission+OSD), all connected to single main battery. Battery is a 4S LiPo with a 5VBEC to power the Raspberry Pi and a12V BEC to power the FPV system.
Log file shows severe anomaly in CTUN ThI behaviour compared to RC Input for channel 3 (CTUN ThI value gets to 2.5 when it should never get over 1 according to ardupilot docs). CURR. Volt. parameter also shows a severe drop in voltage level at the exact moment of the abnormal behaviour in CTUN ThI.
I think most probably the problem was in the FPV system but can not be sure. Maybe too many devices connected to one battery isn´t a good idea also. All the devices continue working if tested individually.
I attach the bin file for the "mission" in case it helps.
Thank you very much in advance and excuse my low english skills
I reviewed your bin file. It looks to me that something is wrong with your physical setup. When thing went bad you had 2 motors revving and the other two going to zero. Things that come to mind are:
1) motors connected to the wrong channels.
2) motor spin direction error.
3) pixhawk not pointing the right direction or the direction parameter set wrong.
Please recheck your set up.
I forgot to tell in the original message that I checked all these things you say and they were all right. in fact, I retired the "extra stuff" of the drone (RPi3 and FPV) and flew normally with the same physical configuration and no problem, so I think it´s clear that this is not the issue.