Vcc spikes to zero in log files. Trouble?

Hi guys,

I have been flying a new setup for 4 days without any major issues. I’m running APM 2.6 with an AttoPilot 90A current sensor. Battery is 8 cell setup.

While checking my logs I stumbled on a worrying issue where my Vcc drops to 0 for a very short time. At least that is what the logs say. About 30-50% og all my logs have these spikes. Can anyone comment on what could be causing the Vcc drops in the logs and what I can do to correct it?

I attached a graph of the Vcc from my log.

Any help would be greatly appreciated:)!

Did I read correctly you use am 8 cell battery !? If yes you are I’m trouble as the PM module supports 4S max, not 8S. So it must be a typo.
Your spikes to zero look like an intermittent bad contact. I would advise checking the end to end powering chain from battery connectors up to the PINs of the FC.

Thanks for the input Hughes. I will definitely check my connections again. However if it is a bad connection and the Vcc is dropping to zero. Would that not cause the Ardupilot to shutdown and fall from the sky and also stop logging? If that is the true I would rather think it is some sort of logging or reading of Vcc error since the copter flies just fine:).

Regarding battery. I am indeed using a 8 cell setup. I do not use the PM module because it is max 4 cell as you mention. I’m using the Attopilot 90A for current and voltage sensing instead. 5V Vcc is supplied to the Flightcontroller via a dedicated switching BEC.

Any further suggestions or thoughts are more than welcome:)!

Almost absolutely certain to be log corruption.

I have had the same issue and this is what Andre-K had to say about it.

[quote=“Andre-K”]yes, I am sure, this goes in the same category as your IMU line:
IMU, 817210, -0.07072348, -9.863644, 8.50345E-25, 2.659501E+36, 7.541347E-29, -5.969283

The insane huge/small values are some sort of error we see , and your voltage/currenttotal zero are probably just 0 because thae are forced into a smaller variable.

If your currentotal, for example - actually were 0 once, it would just start increasing from 0 again.
I do, hovever see small spikes in currenttotal - and have no clue on that variable can drop after those spikes,
Usually one would say that currentotal = currentotal + capacity_used_since_last_time. - so unless capacity used is a negative value - this makes no sense.
so maybe a dev should look at it.

Regarding flyaways, - magnetometer, proper GPS fix are usually the problem, impossible to comment without .log.
I had better luck on complete, fine logs without arifacts with another microSD.[/quote]

Hi Guys,

Thanks a bunch for your inputs! I rechecked my connections and couldn’t find anything suspicious.

If it is a logging issue is there anything I can do to help get it solved? E.g. write a bug report add logs or do tests? Sorry but I am not familiar with how these things are normally handled.

Have a great weekend:)!