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Aug 01, 2021, 06:23 PM
JettPilot's Avatar
Thread OP
Quote:
Originally Posted by David12341234
First flight with DL feedback:

Two issues:
1. Kept getting annoying communication loss / communication recovered pop-up dialogs in q ground control, on Android, connected over bluetooth, over and over, even though the phone was right by the DL TX. Is there a way to connect the DL TX using USB to an Android device, possibly with an OTG cable? I'm thinking that as the the DL TX transmission power increases, it drowns out bluetooth, causing constant connection drops.

2. OpenTx on radiomaster TX16S keeps complaining about trainer signal lost / trainer signal recovered over and over during flight. Anyone know what that is and how to make it stop?
Hi David12341234,

Thank you for your report ! I have no idea what would cause your annoying messages, BUT, the Dragon Link does not drown out its own Bluetooth. Think about it for a minute, with all the Dragon Link systems out there, if this were happening, you would see a HUGE number of complaints about it here in the forum, so not even a possibility....

I Have flown more times than I can count using Bluetooth, and it is fast, stable, and absolutely perfect. I use a laptop with mission planner, so I can not give you any specific theories or solutions with Q ground control, but someone here may know what is causing this.
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Aug 01, 2021, 07:23 PM
Registered User
Quote:
Originally Posted by JettPilot
This might have been added to the latest firmware release, but I am not sure... More importantly, Just use SBUS on the default pin 7, this tiny thing should not keep you from setting up or flying.
It did not, updated the latest one, changed SBUS pin to 7 , mission planner is working better, I passed MAVFTP check super fast like never before, parameters have loaded faster and control is snappier, more responsive and Im shaking in excitement

Cheers,
Aug 01, 2021, 07:24 PM
Eschew obfuscation
KevinW (Qwin)'s Avatar
Quote:
Originally Posted by David12341234
First flight with DL feedback:

2. OpenTx on radiomaster TX16S keeps complaining about trainer signal lost / trainer signal recovered over and over during flight. Anyone know what that is and how to make it stop?
..

If you are using a cable for trainer signal into the TX16S, check your 3.5mm plug.

This same thing happened to me while using head-tracker and discovered that some radios (Jumper and RM) use a 4-pole TPS jack,
(not 3) that jack does not exactly line up with many cheaper made 3-wire TPS plugs. Even just the extruded plastic jacket can interfere with how well it seats.
This causes intermittent and unstable trainer signal caused by the radio/jack/plug moving during use and the annoying voice prompt "trainer signal lost / trainer signal recovered" over and over.

Solution is to use a different "headphone" cable with slightly different plug geometry....Or in my case, I just soldered in a different 3.5mm jack in my radio to work with my cable and jack.

Or...you can just disable the voice alert!
Aug 01, 2021, 07:30 PM
Registered User
Quote:
Originally Posted by David12341234
First flight with DL feedback:

Two issues:
1. Kept getting annoying communication loss / communication recovered pop-up dialogs in q ground control, on Android, connected over bluetooth, over and over, even though the phone was right by the DL TX. Is there a way to connect the DL TX using USB to an Android device, possibly with an OTG cable? I'm thinking that as the the DL TX transmission power increases, it drowns out bluetooth, causing constant connection drops.

2. OpenTx on radiomaster TX16S keeps complaining about trainer signal lost / trainer signal recovered over and over during flight. Anyone know what that is and how to make it stop?
I would be doubtful the DL is interfering with the bluetooth as I leave mine on full power and my bluetooth has never cutout intermittently even when I had my DL mounted to the back of my controller and right next to the laptop.
Aug 01, 2021, 07:31 PM
Registered User
Quote:
Originally Posted by David12341234
2. OpenTx on radiomaster TX16S keeps complaining about trainer signal lost / trainer signal recovered over and over during flight. Anyone know what that is and how to make it stop?
I looked it up and apparently the solution is to change the trainer setting to slave, so it's outputs on the trainer pin instead of listens for input. My theory is that the dragonlink TX is causing some interference as the output power increases, as the issue only happened when the aircraft was over a mile away.
Aug 01, 2021, 07:32 PM
Registered User
Quote:
Originally Posted by fpvgawd
I would be doubtful the DL is interfering with the bluetooth as I leave mine on full power and my bluetooth has never cutout intermittently even when I had my DL mounted to the back of my controller and right next to the laptop.
Are you using Bluetooth on an Android device with Q ground control, or some other setup? It could be a number of things, like some power setting in Android that needs to be changed
Aug 01, 2021, 07:45 PM
Registered User
Hi Mike!

I am posting a few pictures of a new ground station I am building. And one could take a few ideas from that.

Initially, that groundstation was purely manual (I do not have pictures of the original one), but I decided to rebuild it to have it both manual and automatic. You will see both manual control handles and the steppers. It is not yet finished, it still lacks stepper drivers and a control box (based on arduino mega pro 2560).

Some interesting points about it:

The patch has a fixture into which bigger grid antennas can be inserted. The 40 x 60 (26 dbi) definitively will be OK, and most probably the one pictured, 60 x 90 (30 dbi) can also be used. They have a problem that they will shadow close-range receiver.

The whole platform turns on a 12 mm rod (which is not shown on the pictures). Instead of bearings I used "technil", special industruial hard plastic, about 40 mm high and 65 mm in diameter into which the 12 mm rod is inserted.

The steppers have several hall sensors which will be used as limit switches and also to confirm that no steps were missed. Ideally, a stepper with feedback encoder would be best, especially for the azimut, but they are expensive here, around 250 USD. so I did not use that one.

For precision positioning I installed a gear reductor (which I took from a 13 mm hand drill). It has a reduction of about 1:9. I could not find suitable reductors of the size needed, so had to invent, but it was a very biig pain. The good news is that the azimut precision should be in the order of +- 0.7, that would allow the use of the 30 dbi antenna (it has a beam width of only 3).

Do not ever use servoes if you need a precision better than 5. I initally made the whole thing with big servoes, and it was a dismal failure.

The whole station is very compact, should fit into a box like 30 x 30 x30 cm., but again it comes out pretty heavy, in the range of 8 kg. finished.

There some other ideas which I will implement here - namely, it will be absolutely remotely controlled. I will use the NRF24 modules which will communicate from my groundstation to the antenna unit. These modules have a maximum range of about 1 km., and very solid link up to about 500 meters. The DL TX, with modem, wil be also installed on this antenna unit, and all data traffic from groundstation (that is tracker commands, DL TX SBUS stream, and DL TX Modem stream, bidirectional, will be handled by these). The only thing I will have to install is a relay 5.8 ghz line (I have to check if I may have some interferences with the main 5.8 GHz stream) , and after that the Antena unit will be fully autonomous.

You would be able to install it on car roof top to fly from the groundstation inside the car, or from a cabin groudnstation inside the house, with the antenna outside, or even haul the antenna unit to some nearby hill....

Hope it helps to get a few ideas for building...
Last edited by chileflora; Aug 01, 2021 at 08:03 PM.
Aug 01, 2021, 08:11 PM
Registered User
Quote:
Originally Posted by OlliW
well, I don't know what it does, I don't have a DL (but find it a most intersting system, hence my interest LOL) ... if it is "semi-transparent" I actually wonder why it is not fully transparent ... code-wise it should not be difficult to make it fully transparent ...

so, dear DL folks ...
I believe it has a transparent serial link. I have always found it to be so.
Last edited by Marc Dornan; Aug 01, 2021 at 08:16 PM.
Aug 01, 2021, 09:07 PM
Registered User
Big RSSI drop when when circling back home (RTL).

In the graph, I have strong RSSI until I begin to turn around 180 (at the start of RTL, at about 1.5 miles out). This would make me initially think that the plane's motor, esc, or DJI air unit, is interfering, since it is between the RX antenna and the ground station. However, 2minutes later, while still heading the same direction, and same altitude, the RSSI goes back up to 95%+. Is dragonlink bumping up the power, two minutes too late? Channel hopping? What do you think is going on?
Aug 01, 2021, 10:06 PM
Registered User
Quote:
Originally Posted by David12341234
Big RSSI drop when when circling back home (RTL).

In the graph, I have strong RSSI until I begin to turn around 180 (at the start of RTL, at about 1.5 miles out). This would make me initially think that the plane's motor, esc, or DJI air unit, is interfering, since it is between the RX antenna and the ground station. However, 2minutes later, while still heading the same direction, and same altitude, the RSSI goes back up to 95%+. Is dragonlink bumping up the power, two minutes too late? Channel hopping? What do you think is going on?
I think this is just because the polarization of the antennas aren't lined up when you are banking to turn home maybe? thats what happens to me at long distances, when I bank I see a fluctuation of RSSI until im back to around level flight. Usually doesnt happen unless I am a few miles away.


Quote:
Originally Posted by David12341234
Are you using Bluetooth on an Android device with Q ground control, or some other setup? It could be a number of things, like some power setting in Android that needs to be changed
I am using Bluetooth with my laptop and Mission planner !
Aug 01, 2021, 10:25 PM
JettPilot's Avatar
Thread OP
Quote:
Originally Posted by didkodidko
It did not, updated the latest one, changed SBUS pin to 7 , mission planner is working better, I passed MAVFTP check super fast like never before, parameters have loaded faster and control is snappier, more responsive and Im shaking in excitement

Cheers,
Hi didkodidko,

That is really good news !!! There is a lot to learn in this hobby, a lot of frustration, but persistence pays off. Now that you have the experience of doing this, the next setups you do will be easy.
Aug 01, 2021, 10:37 PM
JettPilot's Avatar
Thread OP
Quote:
Originally Posted by David12341234
Big RSSI drop when when circling back home (RTL).

In the graph, I have strong RSSI until I begin to turn around 180 (at the start of RTL, at about 1.5 miles out). This would make me initially think that the plane's motor, esc, or DJI air unit, is interfering, since it is between the RX antenna and the ground station. However, 2minutes later, while still heading the same direction, and same altitude, the RSSI goes back up to 95%+. Is dragonlink bumping up the power, two minutes too late? Channel hopping? What do you think is going on?
That could be a lot of things, I could only give you guesses at this point. If this were my plane, I would not even worry about it unless I started getting failsafes. A quick RSSI drop in itself on a long flight can happen, and is usually nothing to worry about.
Aug 01, 2021, 10:39 PM
JettPilot's Avatar
Thread OP
Quote:
Originally Posted by chileflora
Hi Mike!

I am posting a few pictures of a new ground station I am building. And one could take a few ideas from that.

Hope it helps to get a few ideas for building...
Hi ChileFlora,

Thank you for taking the time to post the information and the pictures !!!! That is awesome, and I got the same kind of grid antenna you have in your pictures, except the smaller version. I will keep you updated on my testing and my results
Aug 01, 2021, 10:52 PM
Registered User
Quote:
Originally Posted by JettPilot
That could be a lot of things, I could only give you guesses at this point. If this were my plane, I would not even worry about it unless I started getting failsafes. A quick RSSI drop in itself on a long flight can happen, and is usually nothing to worry about.
Were your able to see the graph? There was a two minute period of really bad signal, that corrected itself, even though the plane's orientation and heading didn't change. During that time, I was getting constant "communication lost" errors in QGroundControl. Was the TX slow to change power levels?
Last edited by David12341234; Aug 01, 2021 at 10:59 PM.
Aug 02, 2021, 12:49 AM
JettPilot's Avatar
Thread OP
Quote:
Originally Posted by David12341234
Were your able to see the graph? There was a two minute period of really bad signal, that corrected itself, even though the plane's orientation and heading didn't change. During that time, I was getting constant "communication lost" errors in QGroundControl. Was the TX slow to change power levels?
The auto power works very fast, it goes from 25 mW to full power in less than one second when needed. So no, that is not even a possibility.

I have no idea what may cause that, but one question does come to mind. What are you powering your Dragon Link receiver with ???


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