openrcforums

9Xtreme Add 2nd Internal XJT Mod
This mod adds a second XJT module as an internal secondary transmitter, which allows you to use two D-series receivers (PPM protocol with two D-series receivers = 16 channels with TSSI telemtry)
or you can use a combinations of D-series and X-series receivers also to increase the number of receiver channels
(PXX protocol with four X-series (X8R) 8CH receivers = 32 channels with SWR telemetry).

In this mod, I will use the FrSky External XJT module as the primary transmitter with the Txd and Rxd telemetry wires through the back case.
This allows me to use the XJT as a DJT module, the XJT setting needed to change into a DJT: protocol PPM, sub-protocol: D8, dip switch 1: ON (up) and dip switch 2: OFF (down).

At this point in time we are not able to firmware choose which XJT module to have telemetry priority and do not have access to the internal XJT module's manual Bind button (needed for PPM bind), dip switches and to change internally the telemetry Txd Black and Rxd White wires around between S.Port telemetry (PXX with SWR telemetry) and D-Series telemetry (using PPM with TSSI telemetry).
There may be in the future more hardware mods and erSky9x firmware updates that will improve the 9Xtreme features. XJT Module Pin Connections to 9Xtreme Internal Module Connection Pads:
Module Pin 1: PPM / PXX ................................... Pad 9: PPM-PXX signal
Module Pin 2:
Module Pin 3: IN_PWR ...................................... Pad 7: IN_PWR
Module Pin 4: GND .......................................... Pad 8: GND
Module Pin 5: (XJT / PXX protocol / Txd Telemetry Signal Black wire.)

This is as far as I have gotten so far.
More to come!

See here for more 9Xtreme information: (viewtopic.php?f=95&t=7182).

Bob B.

Hi,
I am looking at the possibility of mounting the internal XJT to the 9x Back-Case
and cutting a hole or holes, which would gives access to the Bind switch,
Dip switches, Led light and maybe even the Telemetry pins. Looking also, if there was made, a special XJT face plate (say made with a 3-D printer),
that may help to fit it into place better. I would not want the XJT buttons to be where our fingers are holding the 9x radio when flying.
Other thought I have been thinking and wondering about is placement of the internal XJT module.
Like should it be placed away from, say the main control boards, or can I fit it anywhere I can place it ?

Bob B.

With regards to the telemetry, you could still leverage the use of the optional lcd screen? right?

Conceptually...

I wonder if we could 3d print a "9x backpack" that would allow the two units to sit "side by side" with the antenna of one unit 90deg to the other for diversity? In the modified photo below, the orange would be a 3d-printed "backpack". I would image it would add 2-3 inches of depth.

But a backpack style 3d-print would allow for the back of the stock 9x module bay to be opened up. Cables could then extend from the 9x to "external module", and cabling run from the 9xtreme to the "internal module" bay.

Hi gb21914,
That's a great idea ! Two external module bays.
Could maybe make a all new back 9x case or cut out and glue or screw in a two module bay insert.

Bob B.

Hi,
Have been doing some work on fitting XJT to 9x back case.
Removed the 7 Telemetry Pins from the XJT module (Used Chip Quik which helped a lot when removing the pins and solder). Soldered connecting cable to XJT that will connect to the 9Xtreme Connection Pad pins. Cut holes for Bind and Dip Switches through 9x back Case. XJT placed in 9x Back Case with through holes. Have problem with XJT board hitting Gimbals screws preventing the two case hales closing together. I will have to look at this later to see what maybe done.
One quick idea is to unsolder the Bind/Dip Switch board so it can stay where it is and place the XJT in another location.

Bob B.

What about placing the XJT on the back PCB like I did with a DHT:
Edit:
A picture of radios backside with bind button and LED:
Klaus

Hi Klaus,
Thank you for your photos and suggestions, they are a help.

Bob B.

Two photos showing the connections between the 9Xtreme and the XJT module. Added note: Pin 11 "Battery Voltage" is switched power, which including the "soft power" switch.
This Voltage is then also switched to the Internal and External modules by transistors controlled by the processor.
Pin 9: (PPM/PXX) is the Internal module connection, Pin 7: + power and Pin 8: GND connection.

Bob B.

Hi,
I have been thinking about whether to unsolder the 8 high-rise pins to remove the Bind/Dip Switch board from the XJT module
and connecting 8 wires between them so to be able to hot glue the Bind/Dip Switch board to the 9x back case.
And then installing the XJT module between the Gimbals, looks to be the best place to install it. There seem to be little advantage to no real reason to have access to the XJT internal Bind/Dip Switch board.
I plan to use the internal XJT as number 9 to 16 more channels, for things like FPV cameras, pan and tilt head tracking
and other things that need a receiver channels.

Bob B.

Very Cool modification, is the goal of 2x tx's to get one to handle the 1st 9ch and the other to handle the other 9ch's?
Is this the only way to get more than 9 Ch's?

An XJT using s.port can handle 16 channels on its own, so I suspect this is a matter of a DJT doing channels 1 thru 8 and the XJT handling channels 9 through 24?

LTMNO wrote:Very Cool modification, is the goal of 2x tx's to get one to handle the 1st 9ch and the other to handle the other 9ch's?

No, The first receiver with its 1 through 8 channels to be used with the external XJT module and the second receiver with/numbered channels,
9 through 16 to be used with the internal XJT module.
(What and how many channels depend on what receiver/receivers are being used.)

LTMNO wrote:Is this the only way to get more than 9 Ch's?

No/Yes.
Yes when using two D-series receivers one with each transmitter.
Edit: No, With X-series receivers you can use two receivers with each XJT transmitter module.

Bob B.

But with a single XJT you get 16 channels, and can bind 2 'X' receivers to it, one decoding cahnnels 1-8 and the second for 9-16. You disable the telemetry on one of the receivers.
Also, one 'X' receiver provides all 16 channels on the SBUS port.

Mike.

Sweet! I have one build that can use more than 8 ch. [emoji1]


Sent from my iPhone using Tapatalk

Would a RMILEC signal converter (up to 18ch) work as well?
I have used it with one XJT and one X receiver for 12 channels.
http://www.foxtechfpv.com/rmilec-signal ... -1342.html

I believe so, the X8R and X6R have SBUS output that should work.
I also have a "sketch" that works on an Arduino Mini, takes SBUS in and provides up to 16 channels out.

Mike.

Mike, talking about that and a bit off topic, I'm not sure I have the latest file on that project's thread, on the first post. Would you mind mailing it to me? Or if you find it easier and being a moderator you could just edit my post and upload it. Up to you..
Thanks

João

Hi,
Finishing up installation of this add 2nd Internal XJT Mod. Bob B.

Hi Mike,
When testing this mod, I have a problem My setup is: both XJT modules: ON, using D-series receivers,
external XJT set as a DJT module/PPM/D8 with Com 1 telemetry connected to it.
There is no telemetry coming through when both modules are set to ON, but when I turn the 9-16 secondary internal XJT module
(PXX/D8/ no telemetry connected) OFF, then there is proper telemetry coming through to the external XJT.
The erSky9x-9xt version: V.2636-Mike, DATE: 21.10.2015, SVN:ersky9x-r218, MOD: 9XT.
Could this be because, both XJT's are sending Telemetry at the same time
and so maybe the internal XJT telemetry needs to be turned OFF some how ?

Bob B.

Hi Mike,
Also when I set the internal XJT to OFF, I am getting an alarm BEEPING all the time.
When both XJT's are set to ON, then there is no alarm BEEPING.

Bob B.

I believe switching BOTH dip switches up on a XJT module leaves it in PXX mode, but with telemetry disabled.
I think the problem is that both XJT modules poll the SPort, even if they are not receiving telemetry to send out, so they will collide if both are powered.

Can you locate the source of the beeping? (speaker, or one of the XJT modules).

Mike.

I am setting it up the same way that I use them with my Taranis, ERSKY9X on Taranis (viewtopic.php?f=7&t=4582&start=360#p99734)
which is set to Com2 telemetry (external XJT set as DJT, set to PPM for TSSI/D-series) which works properly.

But with 9Xtreme I have to use Com 1 for telemetry to external module, I speculate this is where the problem maybe.
Also when both modules are on, instead of seeing the TSSI, the telemetry is set as SWR.
The Beeping is from the speaker and I can control the volume of it with P2.

Some more info: When both module are on I have proper control of external (PPM) module to 1st receiver CH3 throttle and Rudder servo
and with internal (PXX/D8) module to 2nd receiver CH9 Aileron and CH10 Elevator, that's work properly.

Bob B.

Are you connecting the internal to COM2? If so, I'm not sure if the XJT module can be directly connected to it or if it needs a level converter..

João

jhsa wrote:Are you connecting the internal to COM2? If so, I'm not sure if the XJT module can be directly connected to it or if it needs a level converter.. João

Hi João,
I am NOT connecting any telemetry to the internal XJT module and I only plan to use it as a secondary module to a secondary receiver Channels 9-16 for when I need more channels.
Using the external XJT (XJT as a DJT module PPM/TSSI) as the primary module using the telemetry wires through the 9Xtreme back-case, plugging them into the the external module telemetry pins.
This way I can have full capabilities of the external XJT module using D or X-series receivers (TSSI or SWR also).
I am only using com 1 telemetry to the external module.
Need to block the Telemetry from the internal secondary XJT module I think, because it must be sending telemetry also.

add edit: I think telemetry must be sent back through pad 7 to the 9Xtreme, but I also need for the PPM/PXX signal, I think?

Bob B.

not to the radio if it is not connected..

João

Hi Mike,
With the Beeping when I zero-out the Alt for the FrSky High Precision Vario the Beeping stops.
It was not doing this before adding the internal XJT module.
Not sure if it has anything to do with the Beeping.

Bob B.

Hi Mike,
I just disconnected the internal XJT module and it still is Beeping until I zero-out the Alt.
I do not remember it working that way, must be a new feature I missed ?

Bob B.

What is beeping? radio or XJT?

João

jhsa wrote:What is beeping? radio or XJT?
João

Hi João,
The Beeping is from the speaker and I can control the volume of it with P2.
I have traced it to when I zero-out the telemetry Alt for the FrSky High Precision Vario the Beeping stops.

Hi Mike,
With the internal XJT module disconnected so that there is no internal module to the 9Xtreme Radio and when I turn ON (in protocol)
the not there internal module, the telemetry changes from the external telemetry module to the not there internal telemetry module.
Can with the firmware, stop the not there internal telemetry module from becoming priority telemetry that is not there
and/or even it is there not to be there so it will use the external telemetry module.

Must be late, I am becoming very worded

Bob B.

bob195558 wrote: Hi João,
The Beeping is from the speaker and I can control the volume of it with P2.
I have traced it to when I zero-out the telemetry Alt for the FrSky High Precision Vario the Beeping stops.

You must have some alarm set somewhere.. Try checking the "AltAlarm" and the "GpsAltMain" options in the telemetry menu, specially the first..

João