What voltage do you need on Crius Board? Flyaway? Cause? Help Required.

[Johnc]

Just had a fly away, still not sure what happened. had a go at down loading log, first time for me, and the only thing I can see is VCC too low?

Log File C:/Program Files/APM Planner/logs/2015-02-25 18-26-36 114.log
Size (kb) 675.693359375
No of lines 12703
Duration 0:08:28
Vehicletype
Firmware Version
Firmware Hash
Hardware Type MPNG
Free Mem 4096
Skipped Lines 1

Test: Autotune = NA -
Test: Balance/Twist = NA -
Test: Brownout = GOOD -
Test: Compass = GOOD - No MAG data, unable to test mag_field interference

Test: Dupe Log Data = GOOD -
Test: Empty = GOOD -
Test: Event/Failsafe = GOOD -
Test: GPS = GOOD -
Test: Parameters = GOOD -
Test: PM = NA -
Test: Pitch/Roll = NA -
Test: Thrust = NA -
Test: VCC = FAIL - VCC below minimum of 4.6v (4.315v)

Does that cause the craft to do it';s own thing?? I am thinking this is why I lost it, poss range issue with radio as well as problem with the board. Does this make sense.
Using 5 volt 2 amp bec which I thought would be enough, will test actual voltage on board and receiver later.
Will load on board vid later and you can hear the Hex powers up and away in a fast decending arc into trees nearby.
Basically went up to tree top height as normal for some air shots, then all well so went higher for more ground coverage,started a 360 deg turn and away she went.
Any comments other than silly boy  and ideas welcome, 
Thanks,
John

Checked esc';s bec output voltage today, 4.9 volts even when wiggling the sticks with copter live & motors turning with props on ( strapped/held down ) only dropped to 4.8 volts.
Does this poss mean that when flying esc';s bec drops voltage as it warms up? Hence the 4.315 v as recorded on the log?

http://youtu.be/8WsmSxd7fio

[Johnc]

When video gets to 1.53 you will hear and see what happens, views on what happens appreciated.
Cheers,
John

[Revs]

As it';s the only thing that looks amiss I';d say it could be the cause. Check for bad/dry solder joins and if poss, make sure the BEC isn';t dropping in voltage as more current drawn from it.

If you can, look through the logs and see how much, if at all, the board voltage varied during the flight.

[Johnc]

Looking at the logs, and I';m not quite sure if I am reading them correctly, but it seems that the throttle signal went to zero which explains the blip you hear just before the motors throttle up & away, also the vcc reading seems to go low at that point, the VCC graph seems to be up & down & not smooth. I will compare it to a flight today with the extra UBEC onto the board.
Will have to check my radio fail-safe to make sure I have it set up correctly, as this might have stopped the flyaway as well.
Any other ideas welcome,
Cheers,
John
Just got the log downloaded from today, it looks worse and still VCC low, as below,
Log File C:/Program Files/APM Planner/logs/2015-02-28 21-55-27 115.log
Size (kb) 708.9951171875
No of lines 13466
Duration 0:10:40
Vehicletype
Firmware Version
Firmware Hash
Hardware Type MPNG
Free Mem 4096
Skipped Lines 1

Test: Autotune = NA -
Test: Balance/Twist = NA -
Test: Brownout = FAIL - Truncated Log? Ends while armed at altitude 3.13m
Test: Compass = GOOD - No MAG data, unable to test mag_field interference

Test: Dupe Log Data = GOOD -
Test: Empty = GOOD -
Test: Event/Failsafe = GOOD -
Test: GPS = WARN - Min satellites: 5, Max HDop: 3.79
Test: IMU Mismatch = UNKNOWN - No IMU log data
Test: Parameters = GOOD -
Test: PM = NA -
Test: Pitch/Roll = NA -
Test: Thrust = NA -
Test: VCC = FAIL - VCC below minimum of 4.6v (4.266v)

Switched off radio and fail safe activates to RTL. So it seems to be board & voltage?????

What is a happening?
Thanks,
John

[Johnc]

Just got back in from a friends house where we did some bench tests on the Hex to look for any possible causes contributing to my flyaway.
The interesting bits where the noise patterns generated on the scope by the UBEC, constant but there all of the time.
Compared to the BEC on the ESC that I was also using which had larger generated noise patterns which where also influenced by use of the throttle which made them worse.
Then whilst motors running did a board push button reset, motors stopped and all waited for throttle down and re-arm sequence before coming back on, same with quick disconnect & reconnect of main battery supply.

Then power off on transmitter as if radio signal lost, board goes into fail safe RTL mode so all good there.

Which leads me to believe that it must be a low voltage spike which locked the board up and led to the flyaway.??  As when it happened all the motors spooled up and the radio had no effective control over the Hex even lowering the throttle made no difference.

Any suggestions welcome,
Cheers,
John


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