MicroArduCopter, 3" props, Omnibus Nano, Success!

dkemxr · October 29, 2019, 3:47pm

OK. For another $15 you would have that (Omni Nano F4). For another $35 you could have a F7 (Kakute F7 mini) in that form factor. This seems negligible for the $/benefit but I understand everyone has their own budget.

anbello · October 29, 2019, 4:02pm

If you have a spare esp8266 you can flash it with this https://github.com/ArduPilot/mavesp8266 to have WiFi telemetry, then enable MAVLink log with LOG_BACKEND_TYPE=2 and obtain logs with MAVProxy and DataFlash Logs module http://ardupilot.github.io/MAVProxy/html/modules/dataflash_logger.html

Maybe a little bit complicated, but I did it some times ago and it worked for me.

DeannaNash · October 29, 2019, 5:40pm

Hi… I recently installed an Omnibus F4 V6 to an Ori32 ESC. Unfortunately, I cannot get the ESC start the motors. So far, I have detected no shorts and plugging in a lipo to the ESC starts the RX and VTX. The FC shows a solid green light and flashing blue light. However, I get no BLHeli startup sound from the Ori32. I am away from my quad right now but do I first need to open BLHeli suite and have the new FC recognize the Ori32?

dkemxr · October 29, 2019, 5:51pm

No. But after configuring the BLHeli passthrough parameters you may want to connect via BLHeli Suite anyway to see if they are recognized. I have that same combination of FC/ESC.

andyp1per · October 29, 2019, 8:35pm

As a really crude approximation put the copter in a hover and use an iphone app to measure the frequency. Not sure how well this will work, but I have used it to find prop resonant frequencies.

Alberto_Ds · October 30, 2019, 6:40am

Thanks Andy, i hope find app like this also for android

Alberto_Ds · October 30, 2019, 6:45am

Thanks Andrea, i will tryed also with this, after want attempt with the dampers

akilesh_mv · October 30, 2019, 7:01am

Hey I am very new to drones. I have pixhawk and I am intrested in controlling the drone using RC control. Can anyone please suggest me how to i control the drone using RC control.These are the questions:
Where should the receiver of the RC be connected?
Does the signal of ESC be connected to RC receiver or to the pins of pixhawk?

andyp1per · October 30, 2019, 8:59am

When 4.0rc2 is out I am happy to do you a version including my FFT changes if you want.

Alberto_Ds · October 30, 2019, 9:34am

Great! Yes! Thanks!

anbello · October 30, 2019, 9:56am

HI @andyp1per I would like to see if I understand well.
The version you are talking about is usable only with Blheli_32 ESC with telemetry.
In the case of Blheli_s ESC is always possible to use the notch filter analyzing logs as described here https://github.com/ArduPilot/ardupilot_wiki/pull/2072
Am I right?

andyp1per · October 30, 2019, 10:09am

@anbello Copter 4.0rc1 includes throttle based dynamic harmonic notch support which you configure using the wiki document you reference. Copter 4.0rc2 should include https://github.com/ArduPilot/ardupilot/pull/12544 which if you have ESC telemetry allows you to configure the harmonic notch without needing to do FFT’s - it just works. If you don’t have telemetry then https://github.com/ArduPilot/ardupilot/pull/11886 would allow you to do the same thing, but that won’t make it into Copter 4.0. I am suggesting I can do a build of rc2 but include https://github.com/ArduPilot/ardupilot/pull/11886 as well.

anbello · October 30, 2019, 10:41am

Thanks @andyp1per if you point me to a fork with this PR merged I can build it for my copters and test it, but I don’t know when I will have the time to report result, I am in a period with next to nothing spare time

andyp1per · October 31, 2019, 11:55am

This includes all of the rc2 fixes so far + my FFT PR

anbello · October 31, 2019, 2:14pm

Thanks @andyp1per, when I will test it I will have to set the parameters as in the first post of you PR https://github.com/ArduPilot/ardupilot/pull/11886 only with INS_HNTCH_MODE=4.
Is it right?

andyp1per · October 31, 2019, 2:31pm

Yes.
The minimum you probably want to configure are something like:

FFT_ENABLE = 1
FFT_MINHZ = 80
FFT_MAXHZ = 350

But the last two will depend on your copter size and motor kv although I think those are reasonable values for most small copters. I also run with a window size of 64 and overlap of 0.75, but that takes more CPU and I have an F7

anbello · October 31, 2019, 3:22pm

And for the other INS_HNTCH_* params do I have to leave all default values?

andyp1per · October 31, 2019, 3:32pm

Defaults should be ok. The best thing to do is first enable the FFT but don’t enable it’s linkage with the harmonic notch (so leave that as throttle-based). Then hover for a couple of minutes and see what the learned hover frequency and ref values are. If these look reasonable then you can first configure the throttle-based harmonic notch with these and try flying. If that works well then compare the log output for the frequency with the throttle-based output. If all looks reasonable there then switch on the FFT linkage.

Or just set the settings and cross your fingers

anbello · October 31, 2019, 3:44pm

Thanks, now is all clear, i think I will go with the “cross your fingers” option

andyp1per · October 31, 2019, 3:47pm

I’m sure that’s fine, the only thing to watch for is dropping the notch too far into your control bandwidth - so for instance if I set MINHZ to 50Hz on my 4" quad it gets very unstable. So higher is safer, but you obviously want to target enough of the throttle range to be useful.