9XR and XJT Telemetry

[rittzy]

Hi, Just wanted to ask the question is this possible, using the XJT in the 9XR and to get telemetry?

I have done the mod to the Tx which is contained in this PDF Document off RCGroups PDF Document which again I don't know if its right because I have seen different guides where they don't use resistors and guides where they use different resistors.

Also I haven't done any wiring to the XJT module because I am not too sure the way it is wired. I know from reading posts by Mike that the 5th pin on the XJT module is used for S.PORT data but not too sure if something else different needs wired up in the modules.

I have looked for ages in google but no avail of understanding this situation any better because I have had conflicting arguments where one person says it's not possible and reading another post on the EX9R part of this forum that someone has got it working including RSSI info.

Just wanting some light shed on the information.

Thanks
Chris

*EDIT*

After reading more and more about it would it be possible to do this as described in the picture where you connect to pin 41 and 42 with the resistor. Then to my understanding you then take wires from the MOSI and MISO and wire them to a RS232 to TTL converter where the MOSI and MISO off he 9XR connect the TTL side of the converter and then run a cable to the back of the XJT module using a cable to connect to the RS232 port?? It doesn't have to be internal, one wire running would be OK if this solution was to work.

Thanks

Chris

[MikeB]

You have done a mod that wires the DJT in directly, using a non-inverted logic signal for the serial data. It also only looks to wire in the data from the DJT, it doesn't include data to the DJT, used to set the module alarms.

The XJT does send the SPort data on the same pin, but it is inverted logic level.
There is a version of the mod that uses the inverted (RS232) signal from the DJT and uses, as you have noted, a RS232 buffer. This buffer also inverts the signal.
See, for example:
http://er9x.googlecode.com/svn/trunk/do ... ryMods.pdf
If you are likely to want to use the DJT in a Taranis, you might also look at:
viewtopic.php?f=95&t=3868&p=57121&hilit ... tky#p57047

If you do the mod as I describe (both the 9XR and the DJT), then you can plug the XJT into 9XR, select PXX as the protocol and the SPort telemetry will then work. I have this working on a 9X, and I have checked the DJT in a Taranis.

Mike.

[rittzy]

Thanks, that's alot clearer after you explained it to me. I will only be using this in the 9XR Tx anyway so the PDF you linked has it all down.

Just having a look at it though it says this "As with all serial communications, care has to be taken with the names transmit (Txd) and receive (Rxd)" It's just a case of following the diagram of the chip that arrives. For example below the arrow pointing in on the RS232 side will be the Tx Signal from the RS232 where as the arrow in on the TLL side (9XR) will be the Tx from the 9XR. Picture reference below.



And I take it only one side of the converter needs connected up for 5v and GND?

Thanks
Chris

[MikeB]

Yes, all you say is correct.

Mike.

[rittzy]

Thanks for the help.

Got the converter and have it soldered together but only seem to be receiving the Rx values and not Tx values. I tried a 4 pin plug wired directly from the back of the XJT into the RS232 convertor no rule out any solder work I done but still not luck. Just wondering if you have any ideas why its not receiving the Rx values for RSSI.

Thanks

[MikeB]

If you are running the XJT in PXX/SPort mode, then it sends SWR instead of Tx RSSI, this is usually 0 or very close to it.

Mike.

[rittzy]

Ok cheers, clears that up.

Thanks for all the help mike!

[floyer]

Hey guys!

I'd read your posts and they looked very legit.
But unfortunately I can't archive your success.

I'm using the 9XR with OpenTX-Firmware 2.0.8 and frsky-setup (for tests like RSSI only). In future I like to display all important data from my flightcontroller at the Display.
I'm also using the XJT-FrSky-Module and the D8R-XP Receiver.

I'd connected the XJT via the external Rxd- and Txd-Connections to my Rs232-TTL converter on the RS232-side and the TTL-side to my 9XR-CPU at MISO and MOSI, like in the .PDF.
My XJT is in D8-Mode (Switch1 ON, Switch2 OFF).

It seems, that my 9XR can't connect to my XJT.
In fact I can't get any data.

Do you have any idea, what could be wrong?
Which firmware do you use?

Greets

[Kilrah]

Telemetry doesn't work on 9XR with OpenTX 2.0.8. Will be solved in next release.

[floyer]

:/ Okay.
When will there be the new release?
Is it possible to get an older working firmware, so I can confirm that my hardware works?

[Kilrah]

There has never been a version of OpenTX where telemetry worked for the 9XR AFAIK. Release should come in a few days, use ersky9xr in the meantime.

[floyer]

Version 2.0.10 was released today and the FrSky-Firmware option works fine (RSSI Rx and Tx is displayed).

But Ardupilot and Mavlink don't work.
Do I have to make some modifications in my Megapirate firmware?

[Kilrah]

How are you downlinking the data from your board?

[floyer]

I'd connected Tx1 (Serial1) from my flighcontroller via an RS232-TTL-Converter to the FrSky D8R-XP Rx-Pin.

(Flightcontroller is Multiwii and Megapirate AIO Flight Controller w/FTDI (ATmega 2560) V2.0 with MegapirateNG 3.0.1 r4-Firmware)

[Kilrah]

Ardupilot and mavlink options require a set of third party transparent radio modems. Mavlink data can't be transferred over a frsky link.

There are various projects to integrate frsky telemetry either in the APM firmware itself or through an external mavlink-frsky converter, but you then need to use the FrSky option on the radio.

Sent via mobile

[izeman]

Version 2.0.10 was released today and the FrSky-Firmware option works fine (RSSI Rx and Tx is displayed).

i'm a total noob and just started flashing my remote. so i played a lot with 2.0.8 for the last 2 days until, thanks to this forum, i found out that 2.0.8. doesn't support telemetry.
so i was searching for 2.0.10 but couldn't find any .hex to flash. and the companion only downloads 2.0.8.
i found the source code. but how do i compile it? or: how would i flash 2.0.10?
thanks a lot!

[Kilrah]

2.0.10 was released yesterday, companion will now download it.

[izeman]

great info. thanks a lot!