Revo atti/stab errors
« on: January 05, 2022, 10:16:31 pm »
I posted this in a different section, but deleted and moved it here for better visability.

Hey everyone, getting back into flying after a long break and playing with some relatively archaic hardware here.  I'm running LibrePilot 16.06 Rhino, and a Revo board on a tricopter. I've gone through the vehicle and transmitter wizards without issue, but when it comes to attempting to fly and tune, I'm running into problems.

It appears that I'm having some sort of internal gyro fault or something. This craft was crashed a few years back, breaking one arm and has since been repaired and there was no apparent damage to the board itself. I'm linking to a video I made demonstrating the problem.



I appreciate any input, as I've done hours of research and have not been able to find any answers.

jdl

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Re: Revo atti/stab errors
« Reply #1 on: January 06, 2022, 08:15:33 am »
Hi,
Sharing my thoughts after watching the video...

It looks like the servo is powered throught the Revo connector and uses the same 5V BEC as the FC.

Coult it be a kind of brown-out reset when the voltage drops (while the servo is operated)? The FC LEDs blink pattern suggests it runs the initial gyro calibration every such occasion..

What about the FlighTime indicator in GCS (Firmware tab)? Does it reset to zero every such occasion? This would indicate FC reboot.

Re: Revo atti/stab errors
« Reply #2 on: January 06, 2022, 08:45:56 am »
Good catch!

When it fails, I see the FC LEDs blinking as if running the Basic AttiEstAlgo like it does at startup.  I also see the ATTI and STAB go red on the GCS.  Both of these things point to the FC rebooting.

BEC is not strong enough to power the tail servo.

You could test by connecting the tail servo to a separate power source.  Black and signal servo wires (only these wires) go to FC.  Black (common) and red wires servo wires go to separate power source.

Does the servo not start up the first time?  It looks like maybe the fancy tail servo is trying to auto-detect what kind of pulse to use (short digital or long analog) and times out.  Long ago I had a similar issue with a gyro and a slow booting receiver.  I installed a switch to power on the gyro (tail servo in your case) after powering on the rest...

Re: Revo atti/stab errors
« Reply #3 on: January 06, 2022, 04:10:33 pm »
Thanks for the diagnosis guys. Can't believe I made that mistake! Here's how power was getting to my tail servo:
BEC to rx, rx ppm to revo, revo to servo.

I have the copter apart now to rewire it. I'm giving the tail servo its own dedicated power supply. I'm also giving the fc its own power, since before it was getting power from the rx. Should the rx have its own power or can it get power from the fc (as in the revo wiring diagrams)?

Also: Is it worth putting the time into this CCD Revo and using LibrePilot?  What GSC are people using nowadays? INAV? Are the Matek fc and pdb offerings any good?

My goal is to have a setup that can do fpv, mapping, and do waypont missions.
« Last Edit: January 06, 2022, 04:41:26 pm by resuwrecked »

Re: Revo atti/stab errors
« Reply #4 on: January 07, 2022, 11:46:59 am »


Should the rx have its own power or can it get power from the fc (as in the revo wiring diagrams)?
Most setups have FC connected to ESC/BEC and Rx getting power from FC.

Also: Is it worth putting the time into this CCD Revo and using LibrePilot?  What GSC are people using nowadays? INAV? Are the Matek fc and pdb offerings any good?
That's a question I can't really answer.  I believe that Inav and ArduPilot are currently more actively developed that LibrePilot.

My goal is to have a setup that can do fpv, mapping, and do waypont missions.
LP GCS has a video gadget if that is what you mean by FPV.  It also does waypoint missions.  Actual mapping is probably better done starting with some research to see what is available, but I would guess that it is mostly post-processing of video with only minor ties to GCS?