While hovering I noticed all motors shut down few times and started again after about 1sec. I power AP board, Reciver and Roll/Pitch servos separately from different ESC BEC (with common GND only). There shouldn't appear brown outs. So what's the reason? [APM CPU 2560, soft v2.5]. Could it have something to do with bad Yaw and Throttle PID settings?
Might be a bad connection, check telemetry logs to see if something interesting there.
Look at my logs for 3rc channel and manual boost. There are signal drops with no reason. Connections are reliable. I use Futaba 10C transmiter and 14FS receiver and they work perfectly. All raw data from 6 sensors work great.
The most interesting is I don't see any problem without propellers. Might it be a problem with high current? I have Lipo directly under the main board.
Can you graph your barometric pressure altitude along with rc3 servo out?
It is weird that the throttle in doesn't match with the rc3_out. It's possible that the short downward spike from the receiver's channel 3 was missed in the logging because it simply didn't catch it.
Do you have an xbee? If "yes" could you try disconnecting it to see if that resoves the problem? I'm not saying that's a permanent solution but if it does it narrows down the problem a lot.
Can you post your logs as well?
Also if you have an atmel programmer, could you try upgrading the ppm encoder software according to this wiki page? I fly using the "ArduPPM_v0.9.87_Arducopter-APMv1.4.hex" version found in the downloads area.
I dont use the Xbee telemetry system and no other systems. Only Futaba FASST one-way transmission. I heard something about PPM encoder update but i thougt it is normaly updated with other APM software. Some time ago I posted about channel interferences. Definitely channel 5()flight mode) disturbed to channel 4 and yaw still jumped. I had to reduce end-points to 75% and problem was gone. Maybe APM have some problems in decoding Futaba channel system? Some experiences?
No the PPM encoder can only be updated with a special AVR programmer. If you have an early APM 1 this could be the issue. When did you get yours?
I use the Futaba radios and don't see any issues, but I also have boards with the current PPM encoder.
I bought all electronic in www.jdrones.com, exactly CPU 2560. Is there something for updating (PPM encoder ?) or this version should work correctly ?
You really need to double check the wires from the radio. This will certainly cause the situation. I've personally seen motors act this way because of a broken RC cable. The cable will break right at the back of the crimp connector where all the stress is. The plastic will hold the wires together, but the vibrations will cause the drop outs.
thanks for suggestion, I'll check wires again.
I soldered the cables from servo 1mm connectors and quite good quality wires. All signal cables were connected with epoxy glue additionally.
low battery ESC failsafe cutoff? Has happened to me. Basically, in a plane the engine would start cutting out, making ti obvious from the ground that you're about to run out of battery. WIth a plane that glides, that's not a bad idea... with a helicopter, not so good. So the ESC has a voltage cutoff perhaps. if it is programmable you can also set whether it cuts engines at high/medium/low voltage to make it more or less sensitive.
So, possibly just need to charge your LiPo?