LibrePilot Forum
Development => Hardware => Topic started by: Zrisst on November 23, 2015, 11:03:45 am
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Hello.
I've got a new OpLink. When it arrived at the mailbox I opened it, plug the antenna, click Upgrade&Erase, USB, all perfect; go to GCS Oplink tab, set 56700, tic in coordinator, TXPower 100%...
Save, disconnect, reconnect... and nothing.
Blue and green light solid. Each 7 seconds two orange lights flashing twice while blue off. No TX, no link.
Device Admin in Windows7 refresh one an another time trying to detect hardware, but nothing appears.
I don't find led meaning anywhere.
It's a faulty hardware?
do I call the shop?
Thanks in advance.
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What appends if you connect Oplink alone (without another board connected) ?
You should see "Oplink" in right/bottom corner and Oplink tab in config.
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What appends if you connect Oplink alone (without another board connected) ?
You should see "Oplink" in right/bottom corner and Oplink tab in config.
I always plug it in alone. After Upgrading/erasing it appears as usual. But when setting transmission power to any value except 0 and rebooting It stops appearing in device list in Windows, and of course in the GCS device list neither in the GCS Config tab (left down button) (Tried it in 4 different computers). Only LEDs behaviour described before.
I have another OpLink that works perfect whit the same procedure, Laptop etc.
The shop is 400km away, if I have to send the oplink back to them is by mail. So I want to be pretty sure that is not something I can't fix before trying warranty.
THNKS.
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Never see an issue like that. If another Oplink works perfect the issue is related to a faulty device.
Something hot on pcb ? maybe a faulty RFM22 module that fail when transmit ?
Try powering with external +5v ?
Look if you see a bad join / short on RFM22 pcb side
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I have same or more issue on my Oplink mini module
firstly plug module to pc and I have see configure menu and change some parameters and save no problem
but when I want upgrade oplink mini I cant make this
and then
I am re flashed bu_oplinkmini.opfw from your site
and now my two pc not recognize oplink mini module (windows 10 and windows 8.1)
module blue led slow flash and yellow always lit
my revo board works perfect and upgradet and no any problem
GCS 15.05 and oplink only usb powering
what is the wrong thank you
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Hi,
Why do no use the last LibrePilot 15.09 release ?
A slow flashing led should say you have updated bootloader (usually not needed) but no firmware.
The procedure for Oplink is :
1 - Disconnect Oplink
2 - Hit button "Update & Erase"
3 - Connect Oplink
4 - Wait firmware update and board reboot
5 - Oplink remains connected
The only stuff active with Oplink alone is his config tab and bottom/right corner say connected.
(https://forum.librepilot.org/index.php?action=dlattach;topic=312.0;attach=618)
(https://forum.librepilot.org/index.php?action=dlattach;topic=312.0;attach=617)
Firmware tab is empty and should be populated by the remote device (Revo for example), when doing the link the Oplink is transparent.
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thank you for fast reply
I used your GCS 15.09 too no any success (last Night)
but I cant see any oplink USB driver/com port in windows device driver screen
"connect oplink" mean remove usb cable or only click connect/disconnect button
when Oplink update or configure need other power source whit USB power
and I am re flashed your bu_oplinkmini.opfw firmware it is okay
I will trying your comments
thanks again
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To use OPlink modem the firmware version on OPLink modem must agree with the firmware on flight controller.
Never ever, set non-zero power in OPlink section when antenna is not connected. Doing so may damage your transmitter or receiver!!
Start with flight controller (OPlink should be disconnected from USB), only flight controller connected to USB
- Make sure firmware is the same as GCS version
- Go to OPLink icon and enable "coordinator" then set power to something small, I set 6, but again antenna MUST be connected before doing that. Powering transmitter by setting none-zero power and not having antenna connected may damage your hardware. Then click save.
- Unplug USB, which should power off flight controller, given that no other power source is connected. You do that to reboot board.
- Plug it back and when GCS connects, you should see in OPlink section the device id, copy it, you need it so OPlink modem knows to whom to connect.[
- Unplug USB, which should power off flight controller. You do that to completly power off flight controller for now, while you will be setting OPlink modem. They shouldn't be connected at the same time.
Now you can configure your OPlink modem
- In GCS go to Firmware section and press upgrade & erase
- Now plug USB connection with OPlink modem, given that Revo is not connected and not powered at this moment.
- GCS should flash your OPlink modem and reboot the board.
- Antenna must be connected before doing this. If it is, go to Oplink section, past device ID of the coordinator you want to connect to and set power same power as on Revo, Save.
Done. Now unplug OPlink modem. Then power up your FC with a DC voltage from regulator or whatever you use on aircraft to power it with (not the usb from the same laptop) and finally connect with USB cable OPlink modem again to your laptop. It should connect with flight-controller. Flight controller must not be connected to the same laptop via USB at the same time when you use OPLink modem.
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I am re flashed bu_oplinkmini.opfw from your site
Remember the bu_file.opfw is only the bootloader, without a firmware flashed the oplink do not work and no connection.
After you flash the bu_file you need this:
1 - Disconnect Oplink
2 - Hit button "Upgrade & Erase"
3 - Connect Oplink
4 - Wait firmware update and board reboot
5 - Oplink remains connected
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thank you
my problem solved whit your helps
Oplink updated okay
thanks
now is a binding modems step
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modems binding is okay
but I cant calibrate tx stick
revo modems configuration screen pic attached
How I can do it
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what do you want to do ?
Oplink on RcRadio for Rc control ?
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yes rc control
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Look this video and description for PPM only:
https://www.youtube.com/watch?v=GYmr0WdFA-s
You can also upgrade to LibrePilot 15.09 :)
Oplink Rc side as coordinator. Flexi port with PPM from radio
Revo side as slave
**********************************************
Oplink PPM only setup - Rc transmitter module -
- set channel range
- set power
- no need to set baudrate, is 9600 for PPM Only
- check "PPM only"
- set as "Coordinator"
- save and reboot
- note Oplm ID
**********************************************
Revo setup - Receiver
- set channel range
- set power
- no need to set baudrate, is 9600 for PPM Only
- check "PPM only"
- set OPLM ID - Rc side - previously noted
- save & reboot
- power Oplink, Revo display Connected
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Hi Laurent
thanks for all helps oplink vehicle control okay
tx stick calibration okay but not motor arms till this time
btw, when I testing rc stick in Revo calibrate screen channel blue bar
is slowing(2second late) move so not moving channels bars whit tx stick same time
is it normal?
sorry for english
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Normal rate is a little slow to avoid traffic over wireless link.
If don't arm, check arm settings and next look systemhealth for alarms
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how I can setting OPLINK for vehicle control and telemetry for use same time
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Exactly the same as previous video and skip the "PPM only" checkbox in both sides.
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thank you Laurent
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Setting a PPM input (flexi or mainport) in ground modem mean you want RcControl and telemetry.
Setting "PPM only" you get only RcControl without telemetry, so baudrate link is set automatically to 9600bds with an extra range because radio noise floor is lower at 9600bds.
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Setting a PPM input (flexi or mainport) in ground modem mean you want RcControl and telemetry.
Setting "PPM only" you get only RcControl without telemetry, so baudrate link is set automatically to 9600bds with an extra range because radio noise floor is lower at 9600bds.
can i use two oplink mini as RCcontrol and telemetry for the nano? thanks
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Yes
First OPLM with PPM on one port (input from Radio) and set as coordinator: Ground side
The other with one port set as PPM for PPM output (Txpin) connected to Flexio PPMin on Nano
Like this:
(http://opwiki.readthedocs.org/en/latest/_images/CC-OPLM-Telemetry+PPM.png)
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(http://images.tapatalk-cdn.com/16/01/01/49d8636516538235dd873537e2375f6d.jpg)
Ok, thanks. I have all my diy nano, oplink, gpsv9, fixed on the 250size quad.
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Yes
First OPLM with PPM on one port (input from Radio) and set as coordinator: Ground side
The other with one port set as PPM for PPM output (Txpin) connected to Flexio PPMin on Nano
Like this:
(http://opwiki.readthedocs.org/en/latest/_images/CC-OPLM-Telemetry+PPM.png)
Can I use the nano's receiver input as PPMin, also pin8?
Because main port for oplink, flexi port for gpsv9. Thanks
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Yes, but Nano has PPM input on Pin4
(https://forum.librepilot.org/index.php?action=dlattach;topic=312.0;attach=984)
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I've just bought an oplink of banggood.
I have successfully upgraded and erased the board.
I changed the power setting and saved successfully but once I power cycle the board it refuses to stay connected.
I believe it is a windows USB issue as the board keeps appearing and disappearing as a USB device.
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If windows/driver issue, try this:
https://forum.librepilot.org/index.php?topic=216.msg1437#msg1437
The blinking stay stable on board ?
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The blinking stay stable on board ?
After saving the change to the power setting and then power cycling the board.
I get a steady Blue light for a few seconds, then the RX/TX lights flash and the GCS briefly shows connected before disconnecting and windows beeps like it does when disconnecting a usb device.
oplink then returns to a steady blue like for a few seconds and the same happens again.
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Try upgrade&Erase again
Disconnect board first
Hit upgrade&Erase button
Wait until reconnect.
If works after that, try setting with small amount of power : in some cases and hardware issues, RF can cause reboot.
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Try upgrade&Erase again
Disconnect board first
Hit upgrade&Erase button
Wait until reconnect.
If works after that, try setting with small amount of power : in some cases and hardware issues, RF can cause reboot.
I've tried this lots of times with the lowest power setting, i'm beginning to suspect a hardware issue.
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After a fresh Upgrade&Erase connecting to Gcs is ok ?
Issue appears after setting some power ?
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I ordered a couple of OPLMs from Banggood a while back, and it appears that one of them also has a hardware problem, although I haven't tested it enough to confirm or to figure out what the problem is.
If it is a problem after adding power to the modem, it is likely a bad modem module.
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After a fresh Upgrade&Erase connecting to Gcs is ok ?
Issue appears after setting some power ?
Yes, after a fresh upgrade i can change most settings except the power setting.
As soon as i set power to something other than 0 it no longer stays connected.
I've ordered another oplink from another provider to see if it's just a duff one.
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So like Brian say, it's a hardware issue with modem....
If you are lucky, try to see if there is a bad solder join or a short on RF modem side.
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Ok. finally sorted. It was a dodgy board from banggood.
They sent me a second board and it works fine as does a board I got from unmanned tech.
In business now. :)
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Pleas help .I make all latest upgrade on my oplink mini and Revolution and all stup like from instruction and I have great conection (betwin Revolution and oplink mini ) but I can't setup rc control.
I check ppm on my rc station (hitec aurora 9x) and all works when I test ppm whit other ppm device.
For signal wire I use last wire on flexi port (picture). Did I miss something ?????
That is my setup :
Oplink Rc side as coordinator. Flexi port with PPM from radio
Revo side as slave
**********************************************
Oplink PPM only setup - Rc transmitter module -
- set channel range
- set power
- no need to set baudrate, is 9600 for PPM Only
- check "PPM only"
- set as "Coordinator"
- save and reboot
- note Oplm ID
**********************************************
Revo setup - Receiver
- set channel range
- set power
- no need to set baudrate, is 9600 for PPM Only
- check "PPM only"
- set OPLM ID - Rc side - previously noted
- save & reboot
- power Oplink, Revo display Connected
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No need to copy paste instructions but better post screenshots from OPlink tab with Oplink connected and next Revo connected.
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thanks
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The Oplink connected to Rc radio (coordinator) should not have any coord Id set, leave blank.
How many channel do you send from your Aurora?. Choose 8 channels max.
Without configuration needed into RcInput you can check the receiver activity when you move sticks.
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i leave coord id blank , in aurora chanel 8 and 9 is set to null but i still dont have conection .
picture from oplink is in attach.
f5soh thanks on your time and help .
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I think i have found the issue
Try the firmware attached.
- Rescue
- Connect Oplink
- Open/load file attached
- Flash
No need to erase settings.
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Thanks .now i am out of home i will test tomorow and report.
Regards Zlatko
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I think i have found the issue
Try the firmware attached.
- Rescue
- Connect Oplink
- Open/load file attached
- Flash
No need to erase settings.
thanks my friend
on the field receiver activity i dont see any change but i can setup aurora 9 and all works.
great yob .
regards Zlatko
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Great :)
I tested here but that confirm that the aurora send a ppm stream with 9 channels.
The max channel supported by Oplink is 8, this means all channels above 8 are ignored. (in your case ch9 value)
Thanks for report,
Laurent
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i got ancient mx-16s fitted with oplink and cant do stick configuration.
it has 8 channels...
Could that help in my case?
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Are these settings ok?
Receivergroup = none
Activechannel = 255
Telemetry is fine but no stick calibration...
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How is connected Oplink to radio ? Pictures ?
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im little a shamed :D ppm signal vas in wrong pin... now it works like a dream.
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Ah.... Good :)
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Hello,
I'm trying to configure an Oplink mini for the ground station. I managed to "Upgrade and Erase" (at least I hope I did), however, when I click on the OPLink tab at the left, I get a 0 value for the Device ID. I can see a Firmware Ver. and Serial Number, but 0 for Device ID. Am I doing something wrong or missing something?
Thanks!
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It won't show a device ID after erase until you configure it. Put on an antenna, set it to a low power, check coordinator, and save. Give it a minute, unplug it, plug it back in, and the device id should be there.
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It won't show a device ID after erase until you configure it. Put on an antenna, set it to a low power, check coordinator, and save. Give it a minute, unplug it, plug it back in, and the device id should be there.
WOW! I was about to try what you just said so I launched Librepilot, plugged the OPLink mini in, clicked on the OPLink icon, and lo and behold, the Device ID is there! LOL! Thanks!
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...
Now you can configure your OPlink modem
- In GCS go to Firmware section and press upgrade & erase
- Now plug USB connection with OPlink modem, given that Revo is not connected and not powered at this moment.
- GCS should flash your OPlink modem and reboot the board.
- Antenna must be connected before doing this. If it is, go to Oplink section, past device ID of the coordinator you want to connect to and set power same power as on Revo, Save.
...
Thanks for posting this OPlink setup help, @Mateusz!
Unfortunately I'm having a problem. Following your instructions I get to the point where GCS flashes & reboots the OPlink transmitter (step 3), but it appears the OPlink doesn't boot up properly. After OPlink reboots GCS recognizes and connects to the 'USB: OPLinkMini' device , but I never see the GCS OPlink page in the configuration section. GCS connection status displays one TX green bar and OPlink transmitter shows only the green 'power' LED lit. That one TX bar connection status in GCS goes out after a few minutes but GCS still shows 'connected'.
This OPlink transmitter is HW rev 1 (from OP kickstart) and was previously flashed with OP firmware. Rescue mode (green solid & Blue strobing LED on OPlink) shows the OPlink reports bootloader version 4. I manually re-flashed the BL to version 4 but it had no effect. This was working hardware (as of a few months ago) and I've never powered it up without an antenna.
If Mateuz or anyone has any suggestions I'd be grateful to hear them!
--Dave
PS - It's great to see LibrePilot getting active! I'm looking forward to contributing as I can in the near future.
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Your issue seems similar to the one described in this page:
https://librepilot.atlassian.net/wiki/display/LPDOC/Troubleshooting
Detected but not really connected and only one tx bar.
Be sure you uninstall the driver from the USB Composite Device that appears while device is connected
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Your issue seems similar to the one described in this page:
https://librepilot.atlassian.net/wiki/display/LPDOC/Troubleshooting
Detected but not really connected and only one tx bar.
Be sure you uninstall the driver from the USB Composite Device that appears while device is connected
Fantastic, deleting the USB device worked. Thank you so much!
Does LibrePilot have a PayPal or a way I can make financial contributions? You can PM me if donations is spamming the thread.
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I have bought at least 4 sets of revo FC /oplink ground combo kits. two won't link at all, the others link and I get about 60db on the graph, but no matter what I do I can't get over a 2 to 3 foot range and it drops out. I have reinstalled USB drivers, interchanged boards. Have I gotten that many crappy boards or am I still missing something.
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There's a pretty good chance you got bad ones. :(
Of the seven oplinks I have two were so far off frequency they wouldn't talk to anything else. Another two had a short circuit in an internal pcb layer on the antenna connector. Those two had a very short range like you're describing.
Four of seven were too bad to use until I repaired them.
I fixed the first two by replacing the RFM22b modules, one of the shorted ones I destroyed troubleshooting and the other I fixed by removing the antenna connector, drilling out the through hole plating, and soldering an antenna directly to the top layer of the board.
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did you find the problem being more on the ground unit or on the revo board?
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My problems were all on the oplink end but I only have one revo so it's hard to draw any conclusion. Most of the time I was running oplink to oplink tests or measuring the frequency on a spectrum analyzer.
Other than the two oplinks that were way off frequency (about 100 kHz) the other's frequencies were close enough to link and work after the antenna connector short was removed.
The antenna short is easy to check if you have a meter. The oplink's center antenna connector pin to the outside shell should read open. If it reads shorted or any resistance value it's a bad board. Someone else who had a low power one read 6 ohms instead of a complete short. Anything other than open (infinite resistance) is bad.
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2 out of 3 shorted 3rd open but won't link. will try your trick on the shorted one's and see what happens. thanks for the help
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forgot to ask, what kind of range should I expect, also the one ground unit that is not shorted has a push button switch next to the antenna, would you happen to know what it's for?
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...push button switch next to the antenna, would you happen to know what it's for?
Originally it was a "bind" button similar to the ones on regular RC transmitters/receivers. Current (and future) firmware ignores it and you set the coordinator ID in GCS to "bind" the modems.
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I get my oplink working with revo for telemetry. But PPM does not work until now.
My radio is HiTec Eclipse 7. Please help me out. Firmware is 15.09. BL is 4 on Oplink and 6 on Revo.
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https://forum.librepilot.org/index.php?topic=1868.msg17892#msg17892
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I have bought at least 4 sets of revo FC /oplink ground combo kits. two won't link at all, the others link and I get about 60db on the graph, but no matter what I do I can't get over a 2 to 3 foot range and it drops out.
I just did buy 4 set of Revo + OpLink just like alnrenny, from two different suppliers, I think... its hard to tell. These two seem different though since one has a black casing for the Revo with the pins color coded in Yellow, Red and Black on the board, a nice black case for the OPlink board, and the redundant 'bind' button is there but only 2 white ports (Main and Flexi),
http://www.thanksbuyer.com/openpiolot-cc3d-revolution-flight-controller-upgrade-version-integrating-oplink-revo-44119 (http://www.thanksbuyer.com/openpiolot-cc3d-revolution-flight-controller-upgrade-version-integrating-oplink-revo-44119)
the other supplier got blue casing for the Revo board, no casing for the OPlink and that has no 'bind' button on it but has 3 white ports (have no idea what the 3rd one is for).
http://www.thanksbuyer.com/openpiolot-cc3d-revolution-flight-controller-board-oplink-mini-cc3d-revo-transceiver-tx-rx-module-40847 (http://www.thanksbuyer.com/openpiolot-cc3d-revolution-flight-controller-board-oplink-mini-cc3d-revo-transceiver-tx-rx-module-40847)
These two suppliers I have noticed are distributed on all major platforms like
Banggood.com
eBay.com
DHgate.com
Aliexpress.com
Thanksbuyer.com
The platforms differs but products are the same.
I was very dissatisfied with the result of trying them out for signal strength.
dont know about dB but the Signal strength meter in the GCS show at best +10 (middle, pointing straight up). The distance was some 3-10 meters indoors.
My problems were all on the oplink end but I only have one revo so it's hard to draw any conclusion. Most of the time I was running oplink to oplink tests or measuring the frequency on a spectrum analyzer.
Other than the two oplinks that were way off frequency (about 100 kHz) the other's frequencies were close enough to link and work after the antenna connector short was removed.
The antenna short is easy to check if you have a meter. The oplink's center antenna connector pin to the outside shell should read open. If it reads shorted or any resistance value it's a bad board. Someone else who had a low power one read 6 ohms instead of a complete short. Anything other than open (infinite resistance) is bad.
Now, inspired by hwh, I just ran a continuity check with a multimeter between the middle pin of the antenna and any one of the surrounding 4. It should not be a short circuit here since then the antenna has no meaning.
. 4 out of 4 revo boards had no continuity - good
. 4 out of 4 OPlink boards did have continuity - bad, 0 or 2 ohms, full short circuit.
I feel good about finally getting an explanation for the poor range but also depressed by this.
I dont want to buy more OPlink boards.
To fix the issue: Maybe some tips on How to repair them? Would be great.
To solve the problem: since the issues with the hardware is widely documented in this forum.
Is it possible for LibrePilot to launch some kind of Product Quality Supplier (QSP) license and have a link to suppliers that sent in good boards? I cannot test board myself for the frequency spectrum mumbo but I really willing to help form such a program. This situation is not really good.
What do you think?
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It is very complicated. There are issues that conflict eachother:
- Design files for Revo and Oplink are released for public under CC-BY-NC license. Which means Creative common (CC) - Attribution (BY) - Non commercial (NC). This implies that legally you are not allowed to produce Revo/Oplinks to sell them and make profit, you can only assemble board for hobby or own use.
- Cloners don't care about Copyrights and make derivatives anyway, some better some worst and you can't control that externally.
- It is ok to use compatible hardware, not derived. There are very nice compatible boards designed from scratch like FC Faclon which are high quality, or Sparky2 boards released fully as open-hardware but authorized supplier chargers 2x the amount that clone costs.
It's also by nature non-profit project, gathering people that like to tinker with hardware and software, more like DIY. On another hand, selling high quality hardware would require commercial steps which might not be the route LP guys want to take.
Best you can do is test hardware you buy, demand from seller full specs and return it if it's not what was advertised. Many suppliers or payment companies have customer/buyer protection and you are allowed to demand refund/return in case if item is broken. It's usually plenty of time to test it. Returning not functional items, eventually force clones to do the hardware properly.
I got my OPlink from Banggood and it works fine with 5 certified sparky2 boards, but I re-call that there was a discussion that some cloned OPlinks had their frequency a bit off (hwh might know more). You need software defined radio (SDR) dongle ($25-$30) to detect that as long as it supports waterfall spectrum AFAIK.
If you have power meter, then lucky you, that's expensive. But if you find short on your board, maybe check for short under magnification glass, sometimes there are solder joints. Maybe all your OPlink boards can be repaired.
Update:
By the way, OPLinks use standard HopeRF RFM22B 100mW 433MHz module, so it should be possible to get one of these
http://shop.top-electronics.eu/20dbm-transceiver-module-433mhz-smd-p-16847.html
and order PCB from OSHPark, and assemble it. Brian (https://forum.librepilot.org/index.php?action=profile;u=264 (https://forum.librepilot.org/index.php?action=profile;u=264)) designed some Nano OPlink boards for his own use https://oshpark.com/profiles/webbbn
but ask him for BOM if you want to play in DIY project :)
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...To fix the issue: Maybe some tips on How to repair them? Would be great. ...
The shorted ones are shorted on an internal pcb layer so they can't be fixed in the obvious way. There are two fixes:
- remove the antenna connector, drill the hole the center pin went in bigger until the short goes away, and replace the connector with a pigtail or a connector that the center pin is insulated where it goes through the board so it doesn't touch the exposed inner ground layer.
- ignore the connector, cut the trace between the connector and the rfm22b module, and solder a pigtail with connector directly to the rfm22b. This one is fairly easy to do. The picture below is an oplink I destroyed testing so it doesn't have the connector or rfm22b on it. The red circle shows the trace to cut and the first pin on the rfm22b that the trace went to is where to attach the center conductor of the pigtail.
The ones that are off frequency f5soh has a change he's been working on that allows you to tune them back on frequency if they're not too far off. I don't think it's been submitted or merged in yet.
...Is it possible for LibrePilot to launch some kind of Product Quality Supplier (QSP) license and have a link to suppliers that sent in good boards? ...
While I don't speak for the project (no one really speaks for the whole project) I don't think any of us would really want to get involved in doing something like that. Both from the standpoint of not wanting to do it and because as Mateusz said, the designs are a type of open source with a non-commercial clause and we don't own the rights to control it.
Almost forgot, the third 4 pin white connector is a debugging port used to debug the firmware. A device called a STLink or a JLink is attached to it.
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Thanks a lot. The responsiveness and depth of knowledge here is just awesome.
As usual it will take me 1-2 weeks to digest it :)
K
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- remove the antenna connector, drill the hole the center pin went in bigger until the short goes away, and replace the connector with a pigtail or a connector that the center pin is insulated where it goes through the board so it doesn't touch the exposed inner ground layer.
hvh, If I go with the option to use the 5 pin original connector, suppose I get the center pin through the board without touching the exposed inner ground layer, How do I get it securely connected to the rfm22b module? By finding the 'trace' indicated on your picture? and then solder it to that? You have a picture? How did you do it?
Alternatively What do you mean by 'solder a pigtail with connector directly to the rfm22b'? What pins on the rfm22b and what thing to solder on there? Picture?
Sorry to ask so much, nu hurry to answer, I will be glad whenever, since this will go nowhere at the moment.
Best
K
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I actually hate those tiny connectors so I never actually did one using option one. You're right, as long as the center pin hole has been drilled out enough to remove the short you can just put a tiny jumper wire to connect the new connector center pin to the spot I circled in red.
For option two you can use a "pigtail" wire like the attached picture. A lot of the oplinks come with one like this or you can buy them on various sites. Just cut off the small connector and solder the wire to the board. The braid goes to any convenient ground like the 4 pins on the connector. The center conductor goes to the rectangular pad to the left of my red circle. Even with the rfm22b module on the board there's enough pad exposed to solder to.
I've misplaced the one I repaired so I can't post a finished picture.
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I just wanted to test if this will work and soldered an antenna straight on to the rf board.
It did! Signal meter now at maximum and stable and no drop outs.
Will do a nicer and more permanent fix.
Thanks a lot!
K
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You're welcome :)
Your pictures make a good example of the fix.
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Now I have done several repairs using the other method, drilling a the center hole larger and re-solder the 5 pin connector. The reason this is preferred is because its impossible to fit the casing on to the OPlink board after you have soldered a cable directly on to the rf board. I have fixed 4 boards with this method now.
Will try to upload the pictures.
It fixes the short circuit but other issues remains...
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So fixing the short cut on the Oplink makes a much stronger signal on the Link Meter and before I could only get 10 m before failsafe it is dramatically improved.
Good.
However taking the quad to the field I discovered that there are generally a good signal strength but interrupted by sudden, short drop out of connection, that will will pick up again to a high level signal, like in 1-2 seconds.
I think this has been reported all over this forum already.
The video clip of the Link Meter I have is from flying around fpv with a Revo board on the quad and a Oplink on the ground. I assume the problem is all on the Oplink side but I do not know. I tried both with a Bluetooth connection to the GCS Mac and with a USB cable to the Mac and it makes no difference better or worse the Link strength or the dropouts. BT seems not to be the culprit here.
The video clip shows that even before taking off the ground and just standing still 10meters away there are dramatic dropouts of the signal strength. Then flying never further than 150 meters and 45m high the signal is pretty constant but the dropouts are there intermittently.
Now I noticed nothing of this while flying but looking at the capture file I see these scary lost signals. If flying later on away say 300 meters or more then it seems 100% sure failsafe will happen and my quad will crash to the ground.
I don't like that at all.
So, is this a case of a bad radio frequency match between the Revo and the Oplink?
How to fix some kind of tuning? I don't have a radio spectrum analyzer and would not know how to use it.
Are the radio modules on the Revo better than on the Oplinks? can they be swopped?
Will try to upload the video link...
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Some clone OpLinks use a bad RF board. The bad RF board is off frequency by more than one channel IIRC. Bad will only talk to another bad.
User HWH has the most experience with this. I recall hearing that someone had some test code that allowed you to retune these bad boards.
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I did a lot of tests a few months ago and found that some of my oplinks were enough off frequency that they wouldn't connect. I fixed two of them by replacing the RFM22b modules with good ones. For the others I made a test branch in my repo that allowed me to tune the oplink frequency manually. The tuning range was enough to tune the oplinks I had so they worked.
I didn't feel up to making a GUI for this so I gave it to @f5soh and he cleaned up my test code and built a GUI for it. There's probably only two or three lines of my code left. :) He made a really nice slider and tuning meter that shows how far the AFC is having to fine tune the frequency so you can get a pair on exactly the same frequency for maximum range. If it's off too far to connect at all his GUI still lets you blindly try shifting the frequency until it connects and then use the meter to fine tune it the rest of the way.
I think it's still just in his repo and there hasn't been a pull request to merge it in yet. I'm not sure but I think it's intended for merge after the 16.09 release is finalized. https://librepilot.atlassian.net/browse/LP-346 In his repo it's part of https://bitbucket.org/f5soh/librepilot/branch/LP-345_RFM22_band . I was supposed to test the band switching but damaged one of the oplinks I converted to 915MHz and forgot to order another one to convert. In fact until now I had forgotten all about it. :(
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Thanks a lot TheOtherCliff and HWH.
Very promising that a tuning tool might become available.
It seems this will be needed for all of the Oplinks sold today since they are all from China to my knowledge.
Will that be part of the GCS as some kind of option in the menus or a standalone thing?
Meanwhile, and as an option, considering replacing the rfboard with a good one as I think Mateusz suggested below by using this http://shop.top-electronics.eu/20dbm-transceiver-module-433mhz-smd-p-16847.html (http://shop.top-electronics.eu/20dbm-transceiver-module-433mhz-smd-p-16847.html)
but this would mean to de-solder the bad one and mount a new one on to it.
Im not sure I have the skills to do that. (the OSH park thing is way over my head).
HWH, How did you do it?
I just feel its worth spending the effort to get the Oplink to work since its so convenient to have control and telemetry in one radio solution.
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I did the first one by sliding a sharpened wooden toothpick under the edge of the rfm22b and then running a soldering iron down the contacts on one edge of it until it lifted slightly. Then the same thing with the other edge.
The second one I used a hot air rework station I purchased on eBay. While this probably is the "correct" way to do it the first one with the toothpicks was actually easier to do. :)
The tuning GUI will be added to the GCS software as another adjustment on the oplink configuration tab.
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Fantastic!
Will try. Have several boards to play with now and a hotair solder.
Thanks
K
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The way I anticipate this to unfold is You get a really good Oplink transmitter board on the GCS side and then you will tune the the Revo boards on the frames you fly to adjust to it. Since the Revo boards will have the same rf chip 100% from China (bad), they will also need to be tuned.
You experienced guys, you agree or not?
Best
K
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Using the ground oplink as the reference and tuning the flight ones to it makes sense to me. It doesn't really matter what frequency they're on as long as all of them end up tuned to the same frequency.
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Got it. Thanks.
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Wanted to share recent progress trying to fix my OPLM boards.
So i have already fixed the short circuit of the antenna on the board. This gave a much better signal strength and range (from before some 3-10m). But from that good level there were short radio drop outs happening like 1-2 times for every 5-7 minutes. So to fix that I hoped that replacing the RFM22b chip for a good one could possibly eliminate it.
I got some RFM22b's from the shop mentioned below.
http://shop.top-electronics.eu/20dbm-transceiver-module-433mhz-smd-p-16847.html
Its actually printed on the back of them 'RFM22B-S REV 3.0'.
(http://RFM22B-S REV3.0.png)
I managed to successfully desolder the old chip from the OPLM and also to solder the new one in place without destroying other small components :P
I have the OPLM on the ground side and then 4 different Revo boards on different frames. I tested the Link meter values of the connections before and after the swop to the new RFM22b chip.
Basically the signal becomes stronger but the dropouts are still there, unchanged.
1. Revo: signal before 9 to +10, with new chip +20 to +25, still have dropouts
2. Revo: signal before +10 to +20, with new chip +25, still have dropouts but maybe fewer
3. Revo: signal before +30, with new chip same +30, still have dropouts
4. Revo with a OPLM as receiver: signal before +20, with new chip same, still have dropouts but maybe fewer
. Distance between TX and RX the same ~7m
. Antennas same for each frame and all of them the same type (dipole half w.lenght)
. Transmitter power set same on all boards, 1.25 mW
. Max and Min channels set same to 250
The video clip show a typical dropout but they can also go all the way to red end bottom and stay there 2 sec before bouncing back to good signal again.
https://www.youtube.com/watch?v=tyhD7hn_VEI&feature=youtu.be (https://www.youtube.com/watch?v=tyhD7hn_VEI)
Knowing there will be radio dropouts for sure and failsafe kicking in to ground my frames is not acceptable to go flying with.
So maybe next step is to try that upcoming frequency tuning method?
Any other ideas?
How about I swop another one of my OPLM boards with the new trusted good RFM22b chips, then use it as receiver to the Revos (not using the onboard chip of the Revo as receiver). The same supplier should be consistent with radio frequency across his own chips right? So then we can rule out the radio frequency as the culprit if the radio dropouts is not disappearing?
Thanks a lot.
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Do you have anything else on 433mhz like an LRS RC that might cause interference?
I wouldn't run min=max. I think it has been fixed to override this with reasonable values, but I would keep 15 channels between them at least. I recall that it can use 12 channels at highest data rates?
It might save you some unuseful work if you can determine that the OpLink is just rebooting. The LEDs will show a reboot. Then the question would be "why?" Dirty power / missing caps would be a first guess. Laptop USB power is sometimes a bit low. Maybe try a short cable to a powered hub or desktop PC.
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Thanks a lot for 3 new ideas!
. I dont think there is any 433mhz sources around here, however a lot of WiFi networks but
What is LRS RC?
I wouldn't run min=max. I think it has been fixed to override this with reasonable values, but I would keep 15 channels between them at least. I recall that it can use 12 channels at highest data rates?
. I am just using the default settings of min=0 and max=250 (maybe I expressed myself unclear).
Should it be set to something else?
. Will try to determine if the OPlink is rebooting or not, but I don't think so. Can it reboot and connect again in 2 sec?
For the power source on the TX ground side I feel confident its stable, 5.0 volt (to the OPlink).
On the air side, I have several different configurations, but the below result was with a 5-6 volt source (same source used both before and after).
This weekend I decided to try and desolder the RFM22b chip from another (non-short circuited) OPlink and replace it with one from the same good source as the one I use on the ground side. Then put the 'new' OPlink as a transceiver to the Revo and disable the Revo's Oplink. All that process went fine.
I was expecting (at least hoping) a higher signal strength, but above all, a stable connexion that would not have any dropouts in a 5 min time. However, the result was not any improvement, really the opposite. Before, the Link meter showed connection at a steady strength of 10+ but after, a deterioration to a steady 8.
I tested for dropouts a number of times, each time 5 min and then I rebooted and connected the units again.
1. 0 dropouts
2. 2 dropouts
3. 17 dropouts
4. 0 dropouts
5. 4 dropouts
6. 8 dropouts
7. 0 dropouts
8. 18 dropouts
9. 2 dropouts
10. 0 dropouts
Intriguing :o
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Run with 115200 data rate on both sides and set min=0 and max=15 both sides (I use max=31). That is what I use. Maybe it will make your reboot times shorter. Also, the higher data rate will keep the channel from being flooded.
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Thanks!
I did change the max setting to 15 but did not change the data speed to highest 115200 data rate but kept it at second fastest 57600, for other considerations its not an option for me to permanently use faster speed.
Then I tested for dropouts 5 times, each time 5 min and then I rebooted and connected the units again. Everything else the same.
Effect seems to stabilize the connection a bit, variation is much lower and the average number of dropouts are down from 5 to 3 but still in every 5 min connection there will be more that 0 dropouts!
1. 4 dropouts
2. 3 dropouts
3. 4 dropouts
4. 2 dropouts
5. 2 dropouts
Worth mentioning is that even though there are Link Meter dropouts, the failsafe did not kick in, I have a buzzer that goes off if real failsafe.
Since reducing the max setting down from 250 to 15 had a good effect, are there any trade offs reducing this number further like to 1 or 2?
What does this setting do?
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Since reducing the max setting down from 250 to 15 had a good effect, are there any trade offs reducing this number further like to 1 or 2?
What does this setting do?
Unless you carefully set it to a known unused frequency range the smaller the number the more likely that some interfering signal will block you. The fields are what they're labeled on the screen, the minimum and maximum frequency the oplink will use. It constantly hops between frequencies in the range you give it. The GUI restricts you to at least 11 channels (high = low + 10). I've used the UAVOBrowser to set it to a lower range when testing but the first time you save on the oplink settings page it sets it back to it's minimum range.
If you set it so it hops between say 430 and 430.5 MHz while there's an interfering signal covering that range you'd be blocked all the time. If it's set to the full 430 - 440 range then that 430.25 interfering signal will only block you a small fraction of the time. If you knew that say taxicabs used 432 - 433 and something else the range 438 - 439 you could set the low to 433.1 and the high to 437.9 to avoid their frequency range.
Another consideration is local laws. Your local laws may restrict what frequencies you can use. You can set the min/max to restrict operation to a frequency range that's legal in your country.
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Maybe you can upgrade to 16.09 and try to reproduce the "dropouts" ?
Since one year, there is some fixes related to the Rssi and connect/disconnect state for OSD.
Here is a one hour scope, just put on/off the transmitter at end to show the failsafe status.
There is the Rssi, Connect state, Throttle value and Receiver status.
Rssi changes are due to various places in the house where i put the transmitter.
(https://forum.librepilot.org/index.php?action=dlattach;topic=312.0;attach=4833)
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Regulations about number of hopping channels aside, IIRC limiting the channel range to something like 0->15 doesn't limit the frequencies to the low range. There is a translation table that is basically random, so you are actually getting 16 random channels spread evenly throughout the full range?
As an aside, the higher the baud rate, the larger the group of adjacent channels it uses simultaneously when broadcasting. I don't remember how this relates to the translation table.
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Regulations about number of hopping channels aside, IIRC limiting the channel range to something like 0->15 doesn't limit the frequencies to the low range. There is a translation table that is basically random, so you are actually getting 16 random channels spread evenly throughout the full range?...
If you select 0-15 you get 16 channels spread between 430.0 and 430.6 MHz. There's no advantage to limiting the number of frequencies it hops on. Only to limiting the actual frequencies to comply with regulations or avoid known interference.
...As an aside, the higher the baud rate, the larger the group of adjacent channels it uses simultaneously when broadcasting. I don't remember how this relates to the translation table.
It doesn't use multiple channels with higher rates, the channels just get wider. The wider channels tend to make it more tolerant of off frequency modules since the AFC will automatically fine tune if the transmitter and receiver channels overlap even a little.
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Thanks all
Maybe you can upgrade to 16.09 and try to reproduce the "dropouts" ?
Since one year, there is some fixes related to the Rssi and connect/disconnect state for OSD.
Thats one good reason to upgrade.
Without a stable, reliable control link with good range, its really not possible to move on to more advanced functions. This has to be resolved.
Thanks for the scope table, that provides more useful information than using the Link Meter. I would anticipate my RSSI will move up and down not because of different locations in my house, they just sit still, but for some other reason.
... and for hwh, I might just experiment with using the standard number of channels again since it should not give any benefits. Problem should be elsewhere...
Best
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Good news.
I have upgraded the OPlink board used as ground transmitter to software from Openpilot 15.05.2 to Librepilot 16.09 and also the same upgrade of software on the Revo board used on the 180 quad.
I am unable to reproduce the dropouts while doing 3 times 5 min connection = 0 dropouts.
Will continue to put it on one full hour using the scope of f5soh.
K
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Not a full hour but 30 min I think and no drop out.
So what was the solution?
. Fix the OPlink short on the antenna connector
. Replace a bad RFM22b chip
. Upgrade to LP 16.09
I will take this to the field and try more ...
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Hi, just some feed back on the latest field tests.
Converting both my 180 and 240 quads to LP 16.09 from OP, plus the fact of fixing the short circuits of the antenna on the OPLM seems to work so well now.
Both quads run Revolution boards with one OPlink board for control and telemetry on the ground side. I am still only flying some 30 m out but at radio max power set at only 25 mWatt and putting the setting of max channels back to default of 250, I have a really steady and strong signal with the Link meter showing 30+. Really happy with this and confidence in the hardware and SW is growing.
Also did run the Autotune function on both of them and its really impressing, they came up with way much better tuning than myself did on manual tuning.
I Would love this feature on Helicopters :)
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Like Hank already say some posts later, setting a 0-250 range is not a guarantee of quality but you should adjust Chanel spectrum to complies with local regulations or antennas that may works better in lower or higher frequencies.
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Got it, thanks Laurent.
Karl
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Thanks for this thread lots of useful information.
Am only using oplink for data not control. LP16.09
Measured resistance at zero had less than 3M range at 100mw on two different quads. Followed advice here, removed 5 pin connector, drilled out center pin and soldered on a pigtail. Now open circuit and range at 25mw about 17M would have expected more. Then again perhaps frequencies are out no way for me to check.
My questions are because I had been using the oplink for more than 3 months with zero resistance could I have damaged the RF module the same as can happen if not using antenna ?
I have oplink as coordinator. Would it improve range if revo was coordinator?
Thanks
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I expect way more than 17m at 25mw. It could be your antennas though. Do you have another one or another set that works well? Try other antennas or antennas from units that work well, so it is known they are correct and good.
Damage from use when "shorted out" is possible, but I would not assume it was damaged until proven. I have run some after the antenna came off with no damage. Hwh developed the "drill it out" procedure and his were OK after the repair.
Cheap clone OpLinks can be badly off frequency. I recall that there is a new adjustment available in LP if you can get and build the version that has it. It may be in 'next' or it may just be in a dev branch so far.
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Thanks for reply was not expecting one so quick.
Your advice worked, changed antennas and now at 40M about -65db very good. Never thought of that.
At the moment cannot check further distance but I am happy with this as I only use link for tuning and to check gps.
Thanks again to you and the LP team.
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...Cheap clone OpLinks can be badly off frequency. I recall that there is a new adjustment available in LP if you can get and build the version that has it. It may be in 'next' or it may just be in a dev branch so far.
It was merged into next around the beginning of January. It shows how far the AFC is auto tuning and lets you fine tune the frequency.
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It was merged into next around the beginning of January. It shows how far the AFC is auto tuning and lets you fine tune the frequency.
fantastic! must try that.