Module advice

[lorenjz]

Hello,

I currently have a Turnigy 9x and programmer on the way. I'm wondering though what module to get. I would like to utilize the frysky telemtry. I'm also interested in the XJT but also get the impression that not much (in the way of firmware) has been developed for it. Is there still a way to use the XJT while waiting for firmware to be developed, or would I be better off getting the DHT module for now and waiting to see what happens with the horizon?

Any input would be greatly appreciated.

Loren

[ShowMaster]

The DJT is the Swiss Army Knife for the 9x telemetry mods and er9x or opentx.
Over 3 years of posts documenting on using it and modifying it is available.
The DHT DIY is another option if you want 16 ch or want to use Frsky and the original Turnigy module and receiver.

With a recent simple mod posted by MikeB the DJT will also work in the new Taranis.
My opinion is if you want a reliable setup buy and fly the DJT until you decide you want to try a Taranis. All the Frsky telemetry receivers will work with so no loss of investment.

[Peter]

As far as I know the xjt does the same now as the djt. When pxx is ready it will do more. I just ordered a xjt.

Verstuurd vanaf mijn GT-I9300 met Tapatalk 4

[ShowMaster]

Good idea about the XJT however like the Taranis is a first generation product. Usually once in wide use issues can appear. If he goes with the DJT we know it's going to work right off. If he decides to sell his radio later it's a small investment to sell with it as a choice.

[lorenjz]

If I get the xjt will I be able to adapt it for use like the djt or will the installation process be more involved because it's a new product?

[Kilrah]

Depends on which version of the mod you want to do - there will be a few changes to the module side that haven't really been looked into yet.

[lorenjz]

Could I install it utilizing PPM for now until Pxx protocol is figured out?

[ShowMaster]

I couldn't find a pinout of the XJT on the Frsky site to be 100% sure so here's what I think.
The DJT module doesn't use the #2 and #5 connector female pins.
They are left open. The 9x has the #2 pin grounded and #5 pin unused as it was for the rf out of the 72/35 MHz antenna. When we do a internal DJT telemetry mod we use these pins to pass the data into the 9x to avoid using the RS 232 connector on the backside of the DJT.
If the XJT uses these pins now or to avoid doing any internal mods the rear RS232 connector can be used. One would make a small hole large enough to pass 2 servo wires through of a cable with a FM servo connector end. This would plug into the XJT or DJT RS233 module connector. I push the pins out of the servo connector so they will pass through a much smaller hole next to the module bay. Then I reinstall the connector shell.
After you do this simple telemetry cable mod you would do the posted 9x telemetry mods normally done.
That's using a Smartieparts board or the soldering mods.
More on that before you do it in the er9x wiki and asking here.
Maybe someone can find and post the new XJT pinouts? The new Frsky site is a work in progress.
To sum it up.
If the XJT can plug into the 9x and work then you can do the the telemetry mod from what I could read up on.
I'm sure others will add more info to this post.

[MikeB]

Many have modified the 9X to support the telemetry to the DJT module with serial data from the module to the Tx on pin 5 and serial data from the Tx to the module on pin 2. This data is at RS232 levels.
The XJT uses pin 5 for the SPort data, and output a heartbeat signal on pin 2. Using a XJT in a 9X modified for DJT will mean the RS232 signal on pin 2 is connected to the heartbeat output.
I've just examined the heartbeat output on a prototype XJT module (internal to the Taranis). It appears to be driven by a transistor in open collector mode, with a 10K resistor in series with the output. This should mean it is safe to use the XJT module in a 9X modified for the DJT.

I described my new method of modifying a DJT for use in the Taranis elsewhere. This method allows the DJT to be used in either a 9X or a Taranis.

Mike.

[lorenjz]

I just had a thought. I'm using a zigbee to provide a telemetry link to the mission planner from my quad. Would implementing another zigbee to provide telemetry data for the 9x be easier or should I stick with my original plan of using the telemetry in the DJT or XJT?

[cae]

If you use the XJT in D8 mode with telemetry receivers other than the X8R, telemetry data will be available on the RS232 port (4 pin) on the XJT module. So using a mod as ShowMaster suggests will work. Note that in D16 mode there is no telemetry on the RS232 port, it is only on the SPORT.

I can confirm what Mike has said about pin 2, plugging the XJT into a 9x with RS232 port connected to pin 2 does not appear to hurt the module. I have not tried in a TX with TTL data on pin 2.

Colin.