Tau Labs CC board resetting due to low voltage - the video

Efliernz

Pete
I had my Openpilot CC board and Hexacopter fail today and the CC board had all of its settings return to default (aeroplane!).
It's a great way to get attention! 6 esc's going bip bip bip 1/2 way up a tree for 10 minutes!The UBEC was only putting out 4.75v. Add that to a binding servo on a camera-mount, and the voltage dropped below 3.5v.

Here is an example of how the board may react if the battery feeding the control board drops to a low level. The motors – some may cut out, others may speed up. I think my reset to default was extreme and I could not replicate that on the table but I could certainly upset the board. It needs power-resetting to make it fully-functioning again after any malfunction.

While I am a techie and I could get a little more into measurements / currents etc, I think this will show enough.

It was not obvious that the voltage was low until the hex failed (thanks to the servo drawing extra current). The hex had flown over 4 hours without a problem - although I suspect that may have been luck now. The servo mount was added 2 flights ago and was pointed all the way down for the first time 2 seconds before I lost control and it free-fell. Time for a bigger UBEC or even better, two separate ubecs. One for the board, 1 for the mount. Common-negative so I can use the same rx.

I normally run separate UBECs for the heli and the mount. I thought that since I was only using one 9g servo, I'd be fine. If I had used a decent ubec I may have got away with this so it really is a "heads up" on how we build and the limits...


On the funny side, I was carrying my new extreme HD video camera and it caught all the good stuff… like being stuck up the tree with me throwing balls at it! That video another time…


Pete

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matwelli

Member
wow - good investigation Pete, will forward this to the OP guys

cant wait to see the vid

could be a case to have a simple bec for the flight controller, and seperate for the servos (Jakubs multiwii board does this)
 

Efliernz

Pete
I have now sorted two ubecs, one for the board, the other for the servo. I have shared this on the OP board (and Ivan) as well.
A good test was had tonight :)

It is coming with me to Palmy this weekend. Looking at the weather map, it might be indoor only - although my new camera is waterproof.

Pete
 



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