Trainer Problem

[trollchen]

Hi Guys,

I'm trying to get trainer mode working with one 9x as master and a Spektrum DX7 as slave. The 9x has open9x installed as firmware. The 9x is working properly and I set up the TRN button. I also set the values on the trainer menu page. But the slave remote still can't control the plane.

Do you guys have any idea why this could be?

Brgds,
trollchen

[ShowMaster]

The 9x requires ppm input of around 5 volts peak to peak, the DX7 like most other TXs today only outputs 1.5 volts or something too low for the 9x to detect.
Gruvin posted an internal mod to the 9x over a year ago on RCGrouos. Since then there has been an external 1 transistor mod posted that gets installed in the trainer cable. There should be all the info here with a search. I was very involved in the discussions but never built it to verify if it works. Hopefully others reading this will jump on with the link to it and comment on how well OT works. The sky board does not have this issue in pretty sure.
So to sum it up, you're not doing anything wrong, it won't work without some level changing circuitry. The fix if it does work is simple.



ShowMaster
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[gohsthb]

Here is the thread where the circuit gets talked about
viewtopic.php?f=5&t=976&start=30
And here is the schematic of the circuit for convenience:

-Gohst

[Helle]

Hy,

or this one.

Helle

[trollchen]

Hey,

I've tried both circuits but none of them worked. On the first one, I have a differential signal from -1 V to + 2,5. Apperently it's not enough to trigger the transitor. Do you have an idea how to change it?

Regards,
trollchen

[IceWind]

Hey did you ended up making this work? I want to do exactly the same, use a DX7 as slave.

[ShowMaster]

My post about a simple external fix was based on the posts I read. Early on I ran into this and at the time a fix that does work was from Gruvin I think. It's a 1 transistor internal 9x mod added to the trainer input on the 4066 IC. This does work but kills the bidirectional mode for simulator tx use.
Mike has some menu option that's involved with all this but it won't work with the mod I think. Hopefully he can clear up all these stories.
I was never able to make the external circuit at the time work. Having spare 9xs I just used them and never went back. This is good to have the discussion again to find a final answer and test it. A lot of great minds here to do that.



ShowMaster
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[Helle]

Hy,


you need a levelshifter!

read this one :
at forum other elektronic Projekts:
viewtopic.php?f=49&t=1933

and this one:
http://fpv-community.de/showthread.php? ... geht-nicht

this shematics realy work, I build it lots of times!

Helle

[ShowMaster]

Does this circuit mount in the master transmitter or can it be installed in the trainer cable?
I'll have to translate to understand the forum discussion on it.
Thank you for helping with a working circuit.
SM


ShowMaster
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[Helle]

Hy,

I don´t touch the master, because masters are ok, problems are the trainer Transmitter
I took it in the trainer cable, or in the trianer Transmitter because I need 5V

Helle

[ShowMaster]

The mod in the master that Gruvin designed will take any ppm signal from 1.5v to 5v and still be OK. A trainer cable mod would be better of course but will need power.
If the mod is in the master then it will work with any tx. I installed the mod a year ago in one 9x and then it would work with a Spektrum, 4 JR's new and 10 years old, and my spare 9x radios.



ShowMaster
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[Kilrah]

The circuit gohst posted does not need power and can be put in the cable. I've seen several reports of success with it.

[ShowMaster]

The circuit gohst posted does not need power and can be put in the cable. I've seen several reports of success with it.

That's the good news we all want to hear. When I saw it posted some time ago I stopped adding Gruvin's circuit as part of my build. I never actually got back to trying it. What's needed here that started this discussion is for someone to try it and report how it works and with the radios they own.
I don't have time for a few days but will try myself to do is first chance so it can go to wiki as fact. Hopefully others will try it sooner and report back. It will be great news if it works.


ShowMaster
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