kennyevo

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OPlink Vehicle control looses it
« on: April 11, 2016, 06:03:03 pm »
Hi!

I'm using oplink with ppm and telemetry at the same time, and sometimes it just looses control (like I don't give throttle).
Any idea?

P.S.:
I haven't tried with PPM only yet, will update the topic later.

f5soh

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Re: OPlink Vehicle control looses it
« Reply #1 on: April 11, 2016, 06:07:55 pm »
Whats the range ? 100m, 1km, 10km ? :)

I think its normal you loose the link at some point.
When link is lost board go into failsafe.

kennyevo

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Re: OPlink Vehicle control looses it
« Reply #2 on: April 11, 2016, 08:33:31 pm »
Hi!
It's about 5 or 10meters (that's why it's strange).
It starts freefalling for 2-5secs and then everything goes normal again.

f5soh

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Re: OPlink Vehicle control looses it
« Reply #3 on: April 11, 2016, 08:51:49 pm »

Connect the Revo to the computer and put your transmitter away, maybe 30m.
Go to Oplink tab and check what you get for bargraph (dbm level) and link quality
 

kennyevo

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Re: OPlink Vehicle control looses it
« Reply #4 on: April 12, 2016, 05:28:45 pm »
The bar goest to 1/3 if I bring the oplink and the revo about 30m away, it's quite low signal strength for 30m :/
And it jumps to 1/3 and 1/2.

f5soh

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Re: OPlink Vehicle control looses it
« Reply #5 on: April 12, 2016, 05:39:35 pm »
Do you see link quality changes ?

Double check antennas.
Assuming you set the same power in both sides and distance/position are the same:
- monitor the dbm value connecting Oplink to Gcs
- monitor the dbm value with  Revo to Gcs.

Compare. If asymmetric there is something wrong with one antenna or module.

Re: OPlink Vehicle control looses it
« Reply #6 on: April 12, 2016, 10:09:43 pm »
I had my quad dropping at some point using OPLink for control and telemety.

Had to to reorient the antennas, and the problem went away.

In my experience it is best to have antennas oriented vertically and away from metal and carbon fiber parts, definitely don't run them parallel to conductive things like aluminium arms...

kennyevo

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Re: OPlink Vehicle control looses it
« Reply #7 on: April 14, 2016, 10:03:07 am »
So I think I've found the root of all evil. Maybe my oplink is faulty, because if I power it from the usb port it works perfectly, but with an external power supply (through main or flexi port) it disconnects in every 2 minutes :/ (even if it's a stable 5.3V from a power supply)

Re: OPlink Vehicle control looses it
« Reply #8 on: April 14, 2016, 01:09:16 pm »
Maybe a faulty diode (D1 on the schematic, a small 3-pin device on the board) or a faulty solder joint on the main or flexi port JST-SH connector or crap wiring?

I'm assuming a glitchy external power supply is out of the question...?

If powering it from USB works flawlessly everything behind the D1 diode should be fine.

Re: OPlink Vehicle control looses it
« Reply #9 on: April 14, 2016, 02:30:26 pm »
I gave up using my OPlink for control.

I had the same issues when using PPM + Telemetry and when using PPM only. I set my failsafe to RTB to save crashes.

When I watched RSSI on the OSD it would go from 100% to 0% and then after about 2 - 3 seconds back to 100%.

This was always at a range of <300m. I used two different ground units with the same result.

Very random and very annoying.
Q450
Revolution

kennyevo

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Re: OPlink Vehicle control looses it
« Reply #10 on: April 15, 2016, 06:40:23 pm »
I was wrong, my oplink control looses connection on 30m, I have set it up with ppm only and 100 tx power on both side..
I'm using the antennas that was bunled with the fc. Both antennas are pointing up, is it possible that my oplink is dead? How can I test which side is dead?

f5soh

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Re: OPlink Vehicle control looses it
« Reply #11 on: April 15, 2016, 07:00:35 pm »
How can I test which side is dead?

Post #5 above

kennyevo

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Re: OPlink Vehicle control looses it
« Reply #12 on: April 15, 2016, 07:48:13 pm »

Re: OPlink Vehicle control looses it
« Reply #13 on: April 16, 2016, 07:33:31 pm »
Mine would disconnect and reconnect. What seemed to resolve the issue was to reduce the number of channels it could use. I'm in the US so I set it to 75 (top number) and 53 (bottom number) .

Sent from my SM-N920T using Tapatalk


kennyevo

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Re: OPlink Vehicle control looses it
« Reply #14 on: April 23, 2016, 03:45:05 pm »
Okay, I think mine is broken, it looses signal after 12-30m even with ppm only and narrowing the channels :/