Jump to content

QX7 Trainer buddy box link


Sheepish
 Share

Recommended Posts

Hi Outrunner, thanks for that I have seen these but not available in the UK until that link.

 

I guess it’s a receiver in a box that can be bound to by the student tx and it shows the four channel plug for sure.  
I was hoping for a simple cable solution but perhaps this is the only way to do this?

Link to comment
Share on other sites

19 hours ago, Ron Gray said:

Just spoken to my flying buddy, he uses his Radiomaster as the Student to his Jeti trainer TX connected with a mono lead but he has a rubber washer on the jack plug to stop it going into the Radiomaster socket too far!

That's interesting try pulling it out slightly and the same with any mono stereo leads you have.

Link to comment
Share on other sites

On 09/08/2021 at 20:07, Capt Kremen said:

To Set The Scene ...

My fellow club instructor and myself both have 'Radiomaster TX16S' Tx.

I have an ancient, (first edition probably), Spektrum DX6i. He has a new Spektrum DX9 to set up on behalf of a new trainee in our club.

 

I successfully set up a wired lead buddy box connection to my DX6i using a twin mono plugged 3.5mm lead - DSC socket to DSC socket in both radio.

 

In a recent 'rainy day' session, we successfully also set up a Radiomaster to DX9 buddy-box connection using a stereo twin 3.5 plugged lead.

(We believe this is a Spektrum brand original lead but it has no distinguishing labels or marks on it, just it's a stereo plugged lead).

 

Wanting a degree of back-up for the working lead used in the DX9 we tried the mono lead which had been used successfully with my DX6i buddy-box set-up.

No joy, yes it powered up the slave Tx but no control signals were possible either way.

So we tried another (different) stereo lead thinking that was probably why it didn't work, again power up of the slave Tx but no transfer of control possible.

 

Puzzled, we tried several other mono and stereo 3.5mm plugged leads, all which work perfectly in their audio operations with phones, headphones etc.

 

Returning to the 'Spektrum' stereo lead, we also discovered it would only work in one direction i.e. the same 3.5mm plug had to be inserted in the same Tx DSC socket, swapping ends and nothing happens. (However, there are no arrows or 'insert this end' etc. on the lead, we only discovered this by pure chance!).

 

Trying one of the other leads again, we discovered a very flaky/intermittent operation could be established if we jiggled the plug in the DX9 socket, almost half way out but this is obviously not satisfactory for safe, reliable training purposes on the flying field.

 

Yes, we know it is possible to go wireless with a module in the Radiomaster but we're trying to keep costs down for the trainee and keep things simple too.

 

  • So, Is the required lead wired differently pin to pin in the plug(s) and/or DSC socket(s)?
  • Does it really have to be a (comparatively expensive, circa £20-00) Spektrum one or can we make a reliable working one out of either the stereo or mono leads we have or similar that we can obtain at any component shop or even phone spares outlet?
  • Has Spektrum or Radiomaster for that matter, now have poor quality DSC sockets? (Remember my ancient DX6i works perfectly with the TX16S and with a mono lead!)

 

Apologies for the lengthy post but I wished to attempt to show we tried our best to cover the obvious solutions such as trying other mono & stereo leads and swapping around.

Thanks in anticipation of the knowledgeable advice I know this community can deliver.

 

 

 

Link to comment
Share on other sites

EarlyBird, I have tried the wiggle test with the mono lead I have and two stereo leads too but the only one I managed to make work so I could try the trainer link was the four channel one.  
The stereo leads would work but it was very difficult to get them to a position where I could use it at all and the mono lead I have refused to work for me at all in the TX16S whatever I did with it.  None of the leads would be stable enough to use in reality as they are now.

 

Denis, thanks for the Capt Kremen link I haven’t seen the whole thing before and it looks like I’m not the first with these issues. I have tried end for ending all the leads I have with no apparent effect but the observation from Capt Kremen would suggest that the manufacturing tolerance of the leads can make a difference to them working or not.  
A study of the Farnell data shows +/- 0.5mm on length on some plugs and also +/- 0.2 mm on diameter so if the whole affair is a bit marginal anyway then these tolerances could be significant I guess.

 

 

Link to comment
Share on other sites

No Problem EarlyBird, it’s been great to have all the input to help solve this.

 

ironically I had the tx’s set up correctly to begin with, its the cable and plug issues that were the curved ball with this one.  
I can remember having issues with buddy box leads years ago but it was always the mono or stereo question.

Link to comment
Share on other sites

Hi Shaun,

You should have a look at THIS for the correct plug (I presume), it's almost 3 mm longer than the standard 4-way plug. have a look at the datasheet referred to on the page.

How it should be wired up is another matter, following the picture EarlyBird placed earlier, Ground should go to the first and second ring from the base, PPM to the third ring, and the tip should remain non-connected.

Link to comment
Share on other sites

Thanks Max Z that looks like it might well be the right length plug for the TX16S socket.

 

As you say wiring is the issue now, the QX7 seemed to be OK with any of the lead I had so perhaps I need to take a look at that TX too to see what the socket looks like in there.  Quite why Radiomaster have made this so complicated I have no idea. ?

Link to comment
Share on other sites

1 hour ago, Sheepish said:

Quite why Radiomaster have made this so complicated I have no idea.

I read somewhere (but I cannot find it anymore) that the "insert detect" is to provide an enable for the PPM signal in port. Left open when the tx is not in function as a trainer,  it would be susceptible to spurious pulses. As those two contacts are shorted via the trainer cable the second ring will be grounded and thus set the enable.

The third ring is for the PPM signal, which leaves the function of the non-connected tip. Alternate use as a headset jack perhaps? Unlikely, as it should (hopefully) work with any standard mono or stereo jack, and probably has a separate socket for that anyway (?).

 

Cheers,

Max.

Edited by Max Z
Link to comment
Share on other sites

2 hours ago, Max Z said:

How it should be wired up is another matter, following the picture EarlyBird placed earlier, Ground should go to the first and second ring from the base, PPM to the third ring, and the tip should remain non-connected.

Sorry but the diagram shows tip as PPM the rings as ground.

 

But the tip should contact C not D. Which means the four way jack is too long as the tip goes past C.

 

image.png

Edited by EarlyBird
jack not socket
Link to comment
Share on other sites

1 hour ago, EarlyBird said:

Sorry but the diagram shows tip as PPM the rings as ground.

 

But the tip should contact C not D. Which means the four way jack is too long as the tip goes past C.

Correct, but that is why I suggested to use the longer jack, intended for this type of 4-way socket, see my link. The tip will then reach contact D, and thus shall be non-connected, and the third ring will reach contact C, so that is where you should wire the PPM signal to.

 

At the QX7 end of the cable you should use a standard mono or stereo jack, where indeed the PPM wire is connected to the tip

 

Btw, I just have a Taranis X-Lite Pro, which has a combined audio and trainer standard 3.5 mm socket. Pushing in a mono or stereo jack registers properly, as a selection appears on the screen allowing me to select between headphones or trainer.

Edited by Max Z
Link to comment
Share on other sites

Got it now ?

 

I think the problem with using a mono, stereo or apparently a Radiomaster lead is because the tip does not reach the socket tip. These jacks all click in and are held in place by being pushed fully home. The socket tip has a bigger contact for that reason. For me this Radiomaster trainer socket is a bad design that is causing problems. Why choose a four way socket when there is no intention to use all four contacts and then supply a four way jack that does not fit. Not a good advertisement?

Link to comment
Share on other sites

Sheepish,

 

Your wire in the photos should work.

 

Attached photos show the trainer / USB board from a Jumper T16 which is effectively the same machine.

It also shows the connector for one of my 2 training modules - this one for Spektrum - with the depth of the connector shown.

This works perfectly for me and has been very reliable, with both modules in use regularly.

 

2nd pic is just to show the module set up.

 

Just a thought, could it be one of the fingers which touch the plug is not quite formed properly so therefore not making contact with the plug?

A quick multi meter test using a stereo lead should confirm the connections.

 

Good luck, I hope you get it cured.

IMG_20211030_123926830.jpg

IMG_20211030_123937478.jpg

Edited by Andy Gates
additional idea
Link to comment
Share on other sites

Thanks for all the extra thoughts.

 

The four channel lead in the picture I posted is a standard lead from eBay, perhaps Radiomaster intended the longer plug type that Max Z found for me?

 

The Radiomaster site shows no option to buy a special cable, only a wireless trainer box, so I would have thought this problem would be more common as I guess there are a few of these TX16 txs are around now.

 

I have tried a whole world of different leads but none yet which have plugs longer than about 14.5mm.  There is no guarantee that a longer plug will do it or if it’s a double ended lead what happens at the QX7 end.
It’s possible that the socket is malformed inside and this is the problem as Andy has suggested.  I was taking a look to see if I can find the small USB board this socket is attached to that I can buy in a reasonable time and price to try this.  I’ve seen them on Banggood and I might order one to try.

Link to comment
Share on other sites

Sheepish,

 

I perhaps did not express myself well enough.

 

You do not need a longer plug. The 4th terminal down from the top is redundant.

 

I suspect the 3rd contact down which is supposed to connect with the waisted tip pin is not making contact at all. Try testing with a stereo cable connected to the trainer socket and with the back of the transmitter open - test between each of the connectors.

 

I suspect a little additional deformation of the 3rd pin down (using a small screwdriver for example) will clear the fault. Then all you have to do is make the deformation a little more permanent.

 

I suspect a replacement board may have the same issue so save your money.

Edited by Andy Gates
Link to comment
Share on other sites

The multiprotocol module supports operating as a receiver to provide trainer mode. One solution to providing trainer functionality is to plug a MPM into the back of the TX16, and use it to receive the trainer data, while using the internal MPM for model control.

 

I agree that trying bending the socket connection is worth trying as that is a solution I referenced earlier in the thread.

 

Mike

Link to comment
Share on other sites

Hi Mike

 

I did think about doing it this way because I already have an iRange X module in the back of the QX7 which I use to control several park flyers with old Spektrum DSM rx’s in.  
If I’d realised what a drama the plug and lead solution was going to be I would have tried it but I was hoping for a simple solution ?.

 

I also have an XRSR rx and I guess I could use this in the module bay in the back of the TX16S too but I also thought this would be more complicated to set up.

When I get the spare board I will have a go at bending some pins and see how I get on.  I’d rather end up with a simple solution that uses a standard lead.

 

Link to comment
Share on other sites

An update on this puzzle with a new exciting addition…

 

I now have a replacement board ready for my TX16S to try but my time has been taken by a variation on this problem.

 

I have a student with two QX7 tx’s running 2.3.14 OpenTx.  The tx’s are brand new so have the Access and D16 capability.  Attempting connect the two by cable to make a student and teacher set up will not work.  It matters not what cable type I use, the trainer function is never recognised.  Pulling a four channel plug almost out of the Teacher TX will sometimes get this to work temporarily but in reality it’s not usable.  
If I now take my older QX7 ACCST only tx running 2.2.4 and make this the master then either of the other newer tx’s will work as a student tx with no problems with any cable I pick plugged in properly to the socket.

 

Speaking to the UK importer of these QX7’s they tried this with their own tx’s and found the same issue and recommended I roll back the firmware to 2.3.10 or older to make this work.  
Good idea but OpenTx has had security certificate problems and companion will not download older than current versions without some back office .dll file manipulation that I don’t understand.  
 

I can get my student flying by loaning him my QX7 but I wondered if anyone else out there has seen this issue?
Or perhaps has the older version of OpenTx they could share?

 

This also makes me wonder if the TX16S issues I was having could also be firmware related and all the cable and plug fuss has very little to do with it?

Link to comment
Share on other sites

I had a chance earlier to try the Radiomaster tx again and to try to get the trainer link to work properly.  
 

I followed the last advice (Thanks Andy Gates) on bending the socket pins around and I did get this to work reliably in the end.  This is not something I would have expected to have to do in a transmitter and is not something I have ever had to do before but it did work in the end.  
I found that the best cable for me was a three section one in the end and looking at where the plug ends up in the socket it’s clear Radiomaster intended a longer plug to be used which is not a standard pattern for any of the audio leads I have been able to easily source.  

Thanks again to everyone who helped with this and I hope the journey helps someone else with the same issue in the future.

 

As for the two brand new QX7’s that do not work together as a teacher/student pair I’m 99% certain this is a firmware issue because neither of them will work as teacher tx’s only ever as student tx’s.  I will have to lend my QX7 to get the student flying and hope that the next OpenTx firmware update solves the problem.  
There was a problem with TARANIS X9d txs not working in trainer mode because the bug was fixed in the last OpenTx update but I think this is an issue too with two QX7’s.  If anyone else out there reads this and has the same issue it would be good to hear from you, especially if you have solved the problem.

Link to comment
Share on other sites

A bit more on this saga if anyones interested.

 

I spent this afternoon rolling back the firmware on one of the QX 7 txs from OpenTx 2.3.14 to 2.3.9 which I downloaded from the FRsky site.  I was not able to compile it with the specific options I wanted but it seems to have solved the non detection of the master trainer function problem.  I need to take some more time to check this properly but it really looks like a firmware bug to me in 2.3.14.

 

I also purchased a Radiomaster WT01 wireless trainer unit to try.  This works well once I understood how to bind it but it does have another challenge as it has FCC firmware flashed onto the built in receiver and at the moment I can find no way of re flashing it with EU LBT firmware to make it easier to use with UK spec tx’s.  I can make it work using a 4in1 module but it’s all extra expense and complication I was trying to avoid.

Link to comment
Share on other sites

  • 5 months later...

I now have a final conclusion to the trainer saga with the two QX7 txs not wanting to act as a master tx.  
OpenTx has recently released version 2.3.15 with the statement that it fixes trainer detection issues with QX 7 txs.
I have updated my QX7 transmitters and this is the certainly the case.  
All the issues that were present before have now gone and the function is easy to use and program.  Also any audio lead I have, mono, stereo or quad now works. 

 

The Radiomaster TX16S still has the problem that the socket they are using is longer than any normal audio jack lead plug and the wireless trainer box they sell, which does work well, will only link in FCC mode as there is no EU LBT firmware are available for it.  I have tried bending socket pins and generally messing with the connection but it’s not something I would want to trust in a normal flying environment.

 

I hope this helps someone else avoid the drama I had try to get this to work.

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...