Problem found see last part of thread, Pixhawk switched flight modes by itself...

Any help would be greatly appreciated. I'm just getting started with the Pixhawk on a XAircraft 650-X8 frame. With Cobra 2217 motors and Afro 20A ESCs using Genfan 11x4.7 props to lift a NEX-5 camera. I made several auto test flights with the equivalent weight of of the camera. Everything was fine. Made several auto test flights with the camera again worked fine (took off, flew to waypoints, landed). Then yesterday I had trouble arming it due to high HDOP but finally it went down enough to arm and hit the auto mode. It flew to the first waypoints properly but then it started rising in elevation (from 150ft which was planned to 200+). it then switch to stabilize mode by itself, Since I had the throttle position low it dropped like a rock (about 50 ft) then switched back to auto mode by itself and climbed back to 200+ ft. It did this twice the second time is when I saw it happen and I switched it to RTL and it came back and landed. Looking thru the logs I can see where it happened but can't determine why. This is a false assumption. ( I'm guessing since I didn't have the Kalman filter on it was getting a bad reading from the barometer.) Turns out it is VCC look at a lower reply. And that somehow triggered the flight mode switch. Today I turned on Kalman filtering and put it in Loiter mode for ~9 min. about all my 3S can handle. it Loitered properly. I then planned a mission to take 45 photos at 50 meters. It flew the mission fine with no problems. Could someone take a look at these logs and let me know what happened? The flight doesn't start until about 60% into the tlog.

Thanks.

Robert

31.BIN

2015-03-16 14-47-41.tlog

House2.txt

Looks like VCC is the problem. Here is my interpretation... when it dropped to 4.91 volts the mode switched to stabilize. Since the throttle position was low this allowed the voltage to rise above 5 volts it switched back to auto mode and continued the mission until the same thing occurred again. I don't know what caused this. I'm using the 3dr power supply and a new 3S 35C 5300 mAh battery. After looking at some APM 2.5 threads I'm assuming the VCC should be a straight a line as possible when graphed. I am powering the Pixhawk straight from the 3dr power supply. I'm using a separate Castle 10 amp BEC to power a older 2 axis gimbal from XAircraft. This is wired in before the connection to the 3dr power supply. Is it possible that gimbal caused the drop in VCC at these two points? There was zero wind that day.

Regards,

Robert

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- - - - Tazmoe > Tazmoe March 18, 2015 at 8:22am
        
        Looks like VCC is the problem. Here is my interpretation... when it dropped to 4.91 volts the mode switched to stabilize. Since the throttle position was low this allowed the voltage to rise above 5 volts it switched back to auto mode and continued the mission until the same thing occurred again. I don't know what caused this. I'm using the 3dr power supply and a new 3S 35C 5300 mAh battery. After looking at some APM 2.5 threads I'm assuming the VCC should be a straight a line as possible when graphed. I am powering the Pixhawk straight from the 3dr power supply. I'm using a separate Castle 10 amp BEC to power a older 2 axis gimbal from XAircraft. This is wired in before the connection to the 3dr power supply. Is it possible that gimbal caused the drop in VCC at these two points? There was zero wind that day.
        
        Regards,
        
        Robert
        
        Tazmoe > Tazmoe March 18, 2015 at 9:08am
        
        Ok I thought the VCC bouncing around was being caused by the 2 axis gimbal being powered before the 3dr power supply but this doesn't appear to be the case. Below is a VCC graph of a test flight just taken without the gimbal being powered. So what gives? Shouldn't the VCC be a steady line on the graph for the Pixhawk?
        
        Regards,
        
        Robert

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Problem found see last part of thread, Pixhawk switched flight modes by itself...

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