9XR & Frsky XJT Telemetry

[jhsa]

Yes, it is.. I have seen it a lot..

João

[ERB]

Hi all,

I'm about to modify my turnigy 9erx to work with a frsky DJT module, but I'm a little bit lost in all the tutorials. I previously upgraded the stock 9x to er9x. After searching the interweb for a couple of days now, I can't really seperate the different options anymore, so a little bit of help would be appreciated:)

Can someone confirm or correct these steps I have to follow:

1. disconnect the 2 220 Ohm resistors from the atmega in the main board of the transmitter. rerout these pads to the top of the controller with a 220 resistor. like it is done in this picture: https://oscarliang.com/ctt/uploads/2013 ... el_220.jpg
2. add wires to the miso and mosi pin of the controller in the transmitter and connect them (with a 470 Ohm resistor for the mosi pin) to the TTL side of the rs232 converter I have. http://forum.turnigy9xr.com/download/fi ... 146399b379
3. connect the rs232 side of the converter to pin 2 and 5 of the header that goes into the djt connector. I have to scratch the leads that go to these pins first
4. in the djt module, what connections need to be made exactly? http://forum.turnigy9xr.com/download/fi ... &mode=view

I guess that should be it, am I correct?

Thanks!

[jhsa]

Have a look at this..

http://openrcforums.com/wiki/index.php/ ... _telemetry

João

[jhsa]

The guide says to isolate both pins 2 and 5 on the back board. actually you only need to connect pin 5 and forget about pin 2 as with ER9X you don't need to program the internal alarms of the DJT. You can, and should, program the telemetry alarms on the radio.
Also pin 5 of the backboard DOES NOT need to be isolated as it only connected the old FM antenna. it is not grounded like pin 2 is.
So, my suggestion is, do not use pin 2, only pin 5. also inside the DJT module, you will only need to connect the resistor to pin 5. You can forget about the other..
If you also want to isolate pin 2, you can of course.. nothing wrong with it..

João

[ERB]

Thanks for your quick answer João!

To check if I understood you correctly: Inside the DJT I only need to make the connection of Txd? Which resistor do I need to connect to pin 5? is there a resistor connected to the txd pin?
http://openrcforums.com/wiki/index.php/ ... y_Lite.jpg

on the outside I only have to connect the rs232 converter to the mosi pin with a 470 Ohm resistor?

excuse my ignorance, but I can't really tell what wire goes where from the given tutorial

[jhsa]

On the wiki link I posted above, there is a drawing of the DJT and the resistors. Another drawing shows a level converter and the connections. It might not be the same you have, but they are basically the same. Have a look.

João

[ERB]

Thanks for your reply! I'm sorry, but I don't really understand what you are explaining.
Do you mean this drawing? http://openrcforums.com/wiki/index.php/ ... y_Lite.jpg

Also I opened the module and found the resistor next to the txd pin. I measured 51 Ohm. Is this the resistor you mentioned? Am i correct that I only have to connect pin 5 from the transmitter to the txd pin? Or do I have to add a resistor into the djt module? To be clear, I'm using a level converter like stated in the drawing I'm refering to.

[jhsa]

Yes, that is the one.. It looks like you don't need a resistor there:) solder a wire from TXD to pin 5 inside the module as shown..
If you are not so comfortable soldering inside the module, you can make a little hole on the back of the radio, pass a wire through it, solder a connector that will plug to module's telemetry port externally, and connect the other side of the wire to the level converter..
This way, you don't need to mod the module..

João

[ERB]

It's all clear now! Thanks for your help

[jhsa]

Good Luck

João

[stereodreieck86]

Hello guys,

I would love to upgrade my 9XR (Non Pro)with FrSky XJT and telemetry. Is the Futaba cable to HF-Modul Method enough to make it work ?

[MikeB]

I missed this question! No, that cable on works on the 9XR-PRO.

Have you done any mods to the radio?

Mike