[DroneSaif]

Hi,

I have now configured a ZMR250 with a revo, osd, Aikon ESC..etc etc.o GPS, as you may have guessed from my other post.

Anyway, I could arm the air carft and was doing shake down.

I had powered up, and armed, and pushed throttle slowly, to about 40%, just below the level where it would fly.

This is when the the aircraft suddenly beeped like it had just started the connection, and it did this 3 times. Needless to say I cannot arm the aircraft until I completely disconnect and re-connect.

I am too afraid to fly now, just in case it did the same while flying.

Any ideas why the revo seemed to re-set itself ?

DroneSaid,

[TheOtherCliff]

This sort of problem would usually be caused by a voltage drop from a bad battery or bad wiring.  The Revo may not have been reset.  It might have been an ESC.

I would measure the pack voltage while you increase throttle to lift off power.  This must be done with props on to provide a true load on the battery.

[DroneSaif]

Hi Cliff,

I had suspected it was bad wiring so I had rechecked the wiring again, and as far as I can tell, the wiring seems to be OK.

I had ruled out the ESC resetting, since the GCS has the "BOOT" indicator turned red when this had happened.


Is there anything from the log that can tell me if there was a voltage drop ? The Revo is powered through a BEC.


I really must learn how to read the logs. What's the point of having all these logs and not being able to read them 

[TheOtherCliff]

I had ruled out the ESC resetting, since the GCS has the "BOOT" indicator turned red when this had happened.

There is a Brown Out Detect and it may be that can show up as a red BOOT indicator on the next boot.  I would measure the battery and also the 5V power going into the FC, under flight load when it resets.  This is a little dangerous, so be careful.

If you want to make sure it isn't a code problem, you can use the Output page to run all motors up at the same time, but without running the flight code.  It should reset from this too, but without flying it.

One other thing comes to mind is excess vibrations.  Are your props damaged?  Did you balance them?

Is there anything from the log that can tell me if there was a voltage drop ? The Revo is powered through a BEC.

When you use the GCS to make a log (Tools -> Start Logging), you can play it back over and over while you watch system health or scopes, etc.

[DroneSaif]

There is a Brown Out Detect and it may be that can show up as a red BOOT indicator on the next boot.  I would measure the battery and also the 5V power going into the FC, under flight load when it resets.  This is a little dangerous, so be careful.

I had a battery monitor connected to the balance cable while I run the motors. 20 minutes of various revving up and down while logging could not recreate the problem.

If you want to make sure it isn't a code problem, you can use the Output page to run all motors up at the same time, but without running the flight code.  It should reset from this too, but without flying it.

Tried this too for about 10 mins and nothing happened.

One other thing comes to mind is excess vibrations.  Are your props damaged?  Did you balance them?

New 3 blades props.

When you use the GCS to make a log (Tools -> Start Logging), you can play it back over and over while you watch system health or scopes, etc.

Will be trying to recreate the problem again tomorrow. Hopefully I will catch it this time.

[TheOtherCliff]

Hmmm...

Measuring the voltage at the battery doesn't help you if there is an intermittent connection between battery and FC (including going through the BEC).  One problem is that the disconnect could be brief enough that it doesn't even show up on a volt meter.  There could even be an intermittent connection problem in the FC.  I guess I am saying that measuring voltage might show you something, but it also may not show you anything, even if that is the exact problem.

Even new props need to be balanced, but I have never had vibrations cause a reboot.

Come to think of it, running motors with it held down probably damps vibrations more than when it is free and ready to take off.  That may be why it is difficult to recreate when tied down.  Maybe tie it down (using Rate mode?), but use the transmitter as if you were flying it.  That may also show no problem.  Then you try to fly it (also Rate mode?) and it has a problem.  This would indicate vibration is at least a factor.

Is there any metal or carbon hardware touching the FC?  Like metal screws or carbon frame etc?

Are all your power wires and motor wires well insulated?  No bare connections with only air between e.g. bullet connectors that could short out if vibration made them touch?

I've got to guess that this is a wiring or FC internal problem that shows up when there is vibration.

Next time it happens, you might quickly look at the Firmware -> FlightTime to determine if it rebooted.  If you plugged the battery in 5 minutes ago and it seemed to reset 1 minute ago, FlightTime will probably say 60 seconds which would prove that it is rebooting.  I assume it is rebooting.  Also, hover the mouse cursor over the red BOOT health and see if it says anything helpful (probably not).

[DroneSaif]

Hi Chris,

Thanks for all the advice, and I think what you are driving at is the trip could be cause by the build quality, specially if vibration is causing it.

I think I am going to strip it down and rebuild, and check each solder, and insulate every part.

I still have to wait for a new GPS anyway, so I have time.

[DroneSaif]

I've got to guess that this is a wiring or FC internal problem that shows up when there is vibration.

Well, I have rebuilt the whole drone. I did not do any re-soldering, but I did improve on insulation.

I have flown the drone twice now, and no incidents. Well, I say fly, but really I just wrestle with it for about 10 minutes each time keeping it hovering over a small area.

All good now I think.