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Just finished the 9X Frsky DJT Telemetry mod...

IBeHoey

The Warranty Voider
#1
over the weekend and wow, it was a doozy. I gotta say, there's no better feeling than doing a bunch of work on something, and having it work on the first try. In hindsight, I should have snapped some pictures before I clobbered it in hot glue but, oh well, it works!!

Has anyone else performed this mod on their 9X? For me personally, the most nerve racking part was working on the DJT RF module. It required making a fine little cut on one of the (1mm in width) traces, removing about 2mm of that trace, and then re-bridging it with a 1k SMD resistor and the RX wire which will connect to the RX pin (#5) via a 470ohm resistor.
9X_Full.jpg 9X_Board.jpg 9X_Back.jpg 9X_FrSky_DJT.jpg

I still need to interface the D8R-II receiver with my FC board in order for it to display the data but the FrSky ER9X firmware is pretty cool. I imagine once I get everything up and running, this little mod is going to be awesome.
9X_Screen.jpg

For anyone else thinking about performing this mod on their 9X, please note, it's not for the faint of heart. However, if you have a steady hand, patience, and a fine tipped soldering iron, it's totally doable and well worth the effort. The only drawback of performing this mod, aside from the tedious soldering, is that, in order to make use of the 2 unused RF pins, #2(6V DC) & #5(RP OUT), you have to isolate them from the internal circuitry. This method is nice in the fact that in doing so, you won't have to worry about running a cable from within the TX to the back of the DJT RF module. Which makes for a clean install but, from this point on, if you want to use any other RF module, for instance the old bundled FlySky module, you'll have to also isolate those 2 pins from within the RF module, or else you'll run the risk of releasing the "magic smoke".

Here are a couple links to the tutorials that I followed.

http://openrcforums.com/wiki/index.php/9x_Full_Mod_Telemetry

http://openrcforums.com/wiki/index.php/9x_Full_Mod_FrSky

http://openrcforums.com/forum/viewtopic.php?f=23&t=430

Once I get everything up and running, I'll post a follow up with some screen shots of the data being displayed on the 9X.

:D
 
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Tritium

Amateur Extra Class K5TWM
#2
Great work.

My 9X has been modded with a SmartieParts board so rather than deal with multiple levels of mods I think my direction will be leave it as is and buy the Taranis from FrSky.

Thurmond
 

Joker 53150

Mmmmmmm, balsa.
Mentor
#3
Having the data on the stock screen is very cool, but is there any advantage to going through the effort when compared to just adding the FrSky display screen for $20.00?
 

IBeHoey

The Warranty Voider
#4
Great work.

My 9X has been modded with a SmartieParts board so rather than deal with multiple levels of mods I think my direction will be leave it as is and buy the Taranis from FrSky.

Thurmond
Thank ya, thank ya.

That's very cool, I was not aware of the Taranis tx from FrSky. After checking it out and seeing the price, it looks like a very promising tx. If I were in need of another tx, I think I would go with it as well, as opposed to just buying another 9X, or even a 9XR and having to re-do all of these modifications. One thing is for certain though, this 9X tx has really opened my eyes at all of the possibilities and awesomeness of having, and running open source firmware on transmitters. So much so, that any tx that I buy from his point on, will have to be open source.

Having the data on the stock screen is very cool, but is there any advantage to going through the effort when compared to just adding the FrSky display screen for $20.00?
To be honest, aside from the "coolness" factor and technical challenge of doing the actual mod, no, not really. For most people it probably wouldn't be worth the effort when, as you said, you can just purchase the LCD addon for $20. That being said, there still are a few key advantages of going this route though. The main one being, the telemetry data is now being handled/processed by the ER9X firmware so you can have the option of assigning alarms and individual settings on a per model basis. Whereas, with only the LCD screen, should you want to go from flying a 2s setup, to say a 4s setup, you would have to reconfigure the settings/alarms each time you switch between the two aircraft. Once again, is this practical or useful for the average RC enthusiast? Probably not, but the great thing about having a tx that runs open source software is that the door is always open for new features/perks to be added on down the road. :D