Spektrofy your Taranis

by HilldaFlyer | February 2, 2015 | (8 Ratings) Posted in Projects

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Spektrofy your Taranis

DIY JR form factor external transmitter module with full range DSM2/DSMX modulation. Build instructions with links to everything you need to know to DIY.

I did it!  --- I made my first electronic DIY electronic circuit board. This article will provide you with the information that I’ve gathered through my project of making a DSM2/DSMX JR external module for my Taranis.

Why go through all this when there is a already made DSM2/DSMX module - OrangeRX? If you are like me, I build planes for the fun of it. I love the challenge of scratch building - which is almost as fun as flying. When I ran out of model memory (10 on my Spektrum DX6i) I was really disappointed. So I started to shop around in order to upgrade my transmitter handset. After a long and extensive search, I decided on a Taranis for a multitude of reasons, mainly because I am drawn to the Open Source programming and versatility. The reviews indicated that the quality was great and a big, big plus, you can get an number of module packs to snap into the back to run any protocol that is to your liking (JR, Spektrum, Futaba, not to mention the long range modules DragonLink, EZ-UHF, etc. I was so convinced that I got one.

I love my Taranis - but I didn’t want to buy a whole fleet of FrSky receivers to replace a all of the DSMX receivers I already have. So, I looked into getting a DSMX module. I only found OrangeRx and DIY mods. I put the OrangeRx Module on my wish list and then did some investigation - I had lots of questions about the function of the OrangeRx Module. I learned a lot from the forums including FT discussion boards (http://forum.flitetest.com/showthread.php?9788-Fr-Sky-Taranis-Chat-Questions-Answers-Share).

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Re: T9X mod to use Flysky module, Frysky module and DSMX mod
by Daedalus66 » Sat Dec 14, 2013 3:15 pm
Yes, the Orange module works fine simply plugged into Taranis.
The drawbacks of going this way, compared to using the module from a DX4 or DX5 are:
1. The Orange module has an awkward antenna setup that sticks out the back.
2. The Orange module doesn't give Model Match or automatic shifting from one type of DSM receiver to another -- you have to do it manually.
These issues may not matter much for your use and it's certainly easy to just use the Orange module as is.

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So, the OrangeRx module is less than what I wanted to settle for… the biggest downer was stated in #2 above: You have to switch from DSM2 to DSMX on the module. In addition, and probably the biggest hassle is that OrangeRX does not support model match. I can only ask why? It makes no sense to me (if you can explain it, please post to the forum - I’d love to hear it). To overcome these limitations, I pursued creating my own DSM2/DSMX module.

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The JR Module Box:

dmyers7 provided the files for making the JR module box and a schematic for connecting the electronic components. Big thanks to dmyers7!

http://www.thingiverse.com/thing:293608

I sent the files and my brother, Bryce, and he printed me the JR Style box which fit perfectly!

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If you don’t have access to a 3D printer - Other options for getting a case are these:

$5.95 + shipping
http://www.jramericas.com/45067/JRPA615/?pcat=333
http://www.rcplanet.com/JR_Radio_Transmitter_Module_Case_p/jrpa615.htm

$9.95 + $8 Shipping.  
http://www.xtremepowersystems.net/proddetail.php?prod=XPS-J1CASE

$9.50 + $2 or $9 shipping. http://www.horizonhobby.com/products/integrated-case-for-jr-compatible-air-module-SPM6817

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Electronics

To get my hands on a Spektrum Tx unit, I bid on every single Spektrum DX4e and DX5e handset on ebay for months without winning the bid. I guess I wasn’t motivated to spend more that $25. Then one day I searched craigslist and snapped one up for $20.

I found several different ways to get the the electronics wired up. You don’t even need a board. The pictures and diagrams on the web provided enough information that anyone can do this, so the big “find” for me was Mouser Electronics. For a few bucks, I picked up all the parts (they do sell individual components). If you are not a DIY, then you can order a kit (board) and the parts. http://johnprikkel.blogspot.com/2014/07/jr-dsmx.html

I used this schematic with one modification - I added a LED with an inline 47 ohm resister between the 3.3v and ground so that I could tell when the unit has power.

http://www.rcgroups.com/forums/showpost.php?p=19988000&postcount=13821


http://www.rcgroups.com/forums/showthread.php?t=2086520


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Source of Electronics

Here is where I got the parts list and ordered from Mouser.
http://johnprikkel.blogspot.com/2014/07/jr-dsmx.html
Here is where someone else got theirs:
http://openrcforums.com/forum/viewtopic.php?f=25&t=541&start=150

Diode 1N4001, Radio Shack 276-1101
Resistor 4.7k-Ohm, Radio Shack 271-1124
Module case and antenna, Spektrum (SPM6817). The antenna connector matches the one on the module from the dx4e. The module fits on a 9x, no problem.
5 pin connector from Hobby King http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=29280
3.3v Ubec from Hobby King http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=17159

If you don’t want to build the power circuit, you can use a premade one.

and follow a different schematic found here. This one can be wired up without a board, just use heat shrink wrap over the two components you will need to solder together.

http://openrcforums.com/forum/viewtopic.php?f=25&t=541&start=150#p48608


Here are some pictures that I found useful.

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Here is my build.

Crack the case of the Spektrum DX4e (I’ve read that this Tx unit is the same as used in the DX5e and DX6i). Remove the 5 screws from the circuit board. Desolder the Tx unit from the front side of the board. I used some desoldering ribbon wick and it came right out. I’ve read that the leftover DX4e unit can be used as slave or simulator… we’ll see about that later.

I had a leftover piece of electronic stripboard that I cut to fit the box. It fit real nicely along with the Tx unit. I soldered the electronics to the board based on the schematic above. Before plugging them into my Taranis or Tx module, I performed the smoke test on the voltage regulator by hooking it up to an external power supply and volt meter. No smoke and 3.3 volts! We’re in business.

Final Assembly

I lined the inside of the box with aluminum foil as a RF shield. I covered the foil in clear electric barrier to prevent any shorts.

Final assembly was hooking up the wires to the Tx pins, connecting the antenna, screwing the back onto the box and snapping the module into the Taranis. I turned on the external Tx and the light came on - no smoke either.

Testing

Will this DSMX module allow more that 10 model memory? This was one of the questions that was raised on the FT forums, by me, to which I didn’t get an answer. My hypothesis is that the Tx chip doesn’t remember which model to bind, but it is a part of the memory based in the handset programming.

Binding a DSM2/DSMX Rx to the Taranis

On the model setup menu, about 3/4 the way down there are settings for Internal RF and External RF.

Set the Internal RF Mode to OFF and the External RF Mode to DSM2 DSMX. When the Mode is changed from PPM to any other mode, the line below appears to set the Rx number, [Bind] and [Range]. To bind the Rx, put the cursor of the Taranis on [Bind], insert the binding plug into the Rx, give it power, and pres "ENT" on the Taranis. After a few seconds, the Rx is bound and the binding plug can be removed.

To test this, I bound two mini OrangeRx receivers (the only unused 2 I have) to channels 11 and 12 (I had already set up 10 models on channels 1 - 10). With both receivers connected to power, I was able to switch from one to the other by selecting the model number on the Taranis.

Here I show the two receivers, both on yet only one is active and this is dependent on the model selection of the Taranis handset. Perfect - now I can have up to 60 model memory between FrSky or DSM2/DSMX receivers. That should keep me in business for a few decades.

All in all - This modification cost $20 for the Tx (plus $6 for the gas to pick it up), the box was free - but lets say I paid $10 for a commercial molded one, electronics were $10, but I got enough to build 3 units, the time spent was 3 hours. Round it out at $50 for the project…

Was it worth it - You betcha!  All the function of the Taranis to my DSMX models without manual switching DSM2 to DSMX, 60 model memory - I just have to smile.

Adding Style:

And just for fun… I created a Spektrum sticker and stuck it to the module.

 

 

My unsolicited advice for someone entering the hobby on purchasing a transmitter. If I knew then what I know now… When I started into the hobby a few years ago, I researched all the different kinds of transmitters, Specktrum, JR, Futaba and Gruapner. Admittedly, the Taranis (or HK Orange Tx) was not yet on the market, but I determined the DSMX modulation had the features I needed for the type of models I would be flying. Here is where some people will start to argue about your model not being compromised for an unreliable cheap $10 receiver. When you get into the models costing several hundreds of dollars and a year to build, then admittedly, the cost of the receiver becomes far less important. I have used OrangeRx receivers for the FT models and have never had a failure yet. So, if someone asked me how to start into the hobby with economics in mind, I would advise them to look on ebay and get a used Spektrum or HK OrangeRx 6 channel receiver. This will get you into the hobby with 10 model memory. If you are still flying and crashing less after a year or two, and you need more features, more channels - the Taranis is the logical choice. It offers limitless features with all the knobs, buttons and switches you will need, 16 channels out (you can bind two receivers), and an open source program that allows for customization. Even without learning any programming, the radio offers the pilot all the convenience of selecting which channels do what.

**********************************************************************************************************************

Resources:

Want true DSMX in your Taranis?


Simple complete blog on making DSMX module with lots of pictures.
How to modify your 9x to the DSM protocol
Here are some links to the sites I frequently visited to make this module:
9x Full Mod DSM2/X
T9X mod to use Flysky module, Frysky module and DSMX module
DIY Spek DSM2 / DSMX JR Module - For my Taranis
Spektrum module for Taranis
JR-DSMX - A Spektrum DSMX compatible JR Module for OpenTX or ER9X
Taranis and DSM2 mods
Beaten to death: Serial DSM Module
SPEKTRUM DSM2 MODULE FROM HP6DSM
Taranis Spektrum RF Module Hack
How to build a true Spektrum DSMX module for Taranis

A complete and excellent tutorial to learn the functions of the Taranis can be found here:
http://open-txu.org/

 
HilldaFlyer February 2015

Comments

sokol on February 3, 2015
I was also considering switching to the Taranis but I did not like the OrangeRX module either. Now you gave me one more reason to switch - as I like to tinker with electronic as well :P

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HilldaFlyer on February 4, 2015
All I can say is, if you got the finances to support a new radio, the Taranis is awesome! With hind sight being 20-20, I would have got this first.
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OrangutangSurfer on February 4, 2015
I have a DX5e transmitter sitting around collecting dust. This would be the perfect way to repurpose it for use in my Taranis. I have heard the DX5e actually has six channels but only five are usable will I have access to all six when I build this module?
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HilldaFlyer on February 4, 2015
You've got it good... If I wasn't clear, the transmitter chips in both the DX5 and DX4 can transmit 6 channels. As a matter of fact, the transmitter I took out of the DX4e is stamped with "DX5e". The module I built will work with all the OrangeRX receivers, and I have confirmed it produces 6 channels of signal, so yes, you will have 6 channels. I haven't tried more channels because I don't have any DSM2/DSMX receivers with more than 6. Good Luck.
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shortside on February 9, 2015
It's my understanding that the module will output as many channels as the transmitter is capable of transmitting. The only limit is on the receiver.
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HilldaFlyer on February 9, 2015
That is great information. I don't own any DSM2/DSMX Rx with more than 6 channels, but that will be something I've got to try. Seems logical that the limitation would be in the radio programming. We'll see...
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Bob T on July 6, 2016
Shortside and HildaFlyer,I have tried a Dx6i and Dx8i module in my Taranis Plus. No matter what, I am only able to get six channels out using Orange or Specktrum eight channel receivers. It seems the limitations are in the Taranis radio on what it can send to the external transmitter.
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HilldaFlyer on July 6, 2016
Thanks for looking into this. At this point my knowledge is getting pretty exhausted. I would have guessed that since module packs will extend to 8 channels, so will a DIY module. Might have to talk to the Taranis folks about this.
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SelmerSlowflyer on March 15, 2015
Did this mod today and it is really very simple to do when using the Hobbyking Ubec as 3.3V supply. Thanks for this article.
One thing im missing in the article is a short description how to bind the receiver. Previously i was just using PPM on the external RF and was now wondering how to bind receivers to the spektrum module. Then searched some time and discovered that the Taranis has an extra mode for DSM2 or DSMX which makes the bind button appear.
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HilldaFlyer on March 18, 2015
I can add that info to the article. I believe the OrangeRX module uses PPM and has a bind button. Binding using a modified DSM2/DSMX box is fairly straight forward. For others reading this for an answer - on the model setup menu, about 3/4 the way down there are settings for Internal RF and External RF. Set the Internal RF Mode to OFF and the External RF Mode to DSM2 DSMX. When the Mode is changed from PPM to any other mode, the line below appears to set the Rx number, [Bind] and [Range]. To bind the Rx, put the cursor of the Taranis on [Bind], insert the binding plug into the Rx, give it power, and pres "ENT" on the Taranis. After a few seconds, the Rx is bound and the binding plug can be removed. A complete and excellent training for setting up the Taranis can be found here: http://open-txu.org/
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frankstrudel on September 20, 2015
Has anyone tried using the remains of the Tx as a slave buddy box to the master Taranis?
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HilldaFlyer on September 20, 2015
Let me see if I understand you correctly. Are you asking if the remains of the DX4 that I removed the transmitter from be used as a input source for a buddy box? I can check on that.
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frankstrudel on September 20, 2015
Exactly my question! Thank you :D
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HilldaFlyer on September 20, 2015
I just checked it out. The answer is yes. I just hooked up the DX4e to the Taranis with a buddy cord and was able to use all four stick channels to control the plane. Should work as a simulator box as well since signals are still being put out through the plug.
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frankstrudel on September 20, 2015
Fantastic thank you!
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Medicschors on August 21, 2015
Can a dx6 be used for this mod? Have one that i am not using and would love to dump my orange module!
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HilldaFlyer on August 21, 2015
Sure can, it will work very well. I do not know if there are any advantages for using a DX6 rather and DX5 module, like power/range. I have a DX6i radio that doesn't get much use now that I have a Taranis. However, in a little bit I'll be publishing another Taranis modification where I use my DX6i as a wireless training box. Now it is getting used again. Just be sure you really want to get rid of it before you tear its hear out. :) For me, I'd keep my eyes open for a dropped/broken or cheap DX4 or DX5 for the mod and keep the more expensive DX6 for buddy or other models for friends - just my two bits.
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spooledone on September 15, 2015
This project relies upon a software BIND button, right? This wiuld mean that the transmitter software would have to support this type of binding, as opposed to holding the bind button down on a OrangeTX module. I run a Turnigy 9x, with OpenTX (regular release). Sounds like I'd need to change the software on the 9x to the openTX version that supports the dsmx module? Or are there any hacks/mods to place a physical Bind button on this module?
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HilldaFlyer on September 20, 2015
The binding of the external module is the same as for the internal. There is a line in the Taranis' setup menu that says "BIND". Click on it and the transmitter is in binding mode and will bind with the receiver that is also in bind mode and sending the binding initiation signal. It does not need a button on the external module like the OrangeRx module.
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Ergo30 on October 8, 2015
Great article, would you mind if I ask a question here as I have scoured the internet and am really struggling. I need the RF output power in mW of the standard Taranis without any module in but cant find this information anywhere. I am currently going through commercial training in the UK and desperately need this information, I don't suppose anyone knows it here do they?

Thanks

Simon
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rockyboy on November 16, 2015
This project worked out great for me! But I can confirm that if the donor DX5e radio doesn't have the "X" graphic on the front cover plate, it won't bind with newer DSMX models like the NanoQX. Still worked fine with my Sukhoi Su-26m however. Once I got a newer donor radio (with the X graphic) I swapped radio modules and now my Taranis can bind to both the NanoQX and Sukhoi just fine.
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DanielMedStortD on January 23, 2016
Ia it possible to do this mod woth a dx8 module? Got one i can get for a cheap buck and was just wondering :)
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HilldaFlyer on January 24, 2016
Sure can. I haven't looked at a dx8 transmitter module, but if it is the same size, no problem.
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China_White on April 23, 2016
I tried with a DX8 rf module and it didn't work. Couldn't find much info on why it wouldn't.
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Bob T on July 6, 2016
Hmmm, strange you could not get the Dx8i module to work. I was able to, but still only got six channels out, so I went back to the Dx6i. Make sure the Taranis has external module OFF, and internal module to Dsm2 DsmX (there is a place for both of these at the same time, however, if your receiver is a Dsm2, you may need to have both set as Dsm2 Dsm2)
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cavityburn on June 8, 2016
So, i just built this version of the Mod, and I have a question with voltages.
I see 7vdc from the Taranix Pin, and per the design, there is a 4k7 resister between the PPM/Signal line and 3.3v Lead to the DSM module, and with my VOM, I am seeing roughly 3vdc on the lead going TO the DSM. I have not soldered up the DSM to the circuitry yet because I don't wanna risk burning up the DSM mod with 2 voltages. Is there supposed to be voltage on the signal line to the DSM?
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HilldaFlyer on June 8, 2016
Interesting observation. Had I checked the voltages of those pins, I would have asked the same question, but I didn't check the voltage on the PPM pin.

Just for you, I removed my DSMX module, opened it up and tested. Here are the voltage readings coming out from the Taranis from top to bottom as labeled in the photos above:
I am using Pins 1, 3 and 4 to feed the module.
Pin 1 7.38 v
Pin 2 0.66 v
Pin 3 7.69 v
Pin 4 GND No measure
Pin 5 0.0 v

Here are the pins on the DMSC transmitter, reading left to right with antenna up and pins on the bottom right.
Pin 1, GND
Pin 2, 3.29 v
Pin 3, not used
Pin 4 not used
Pin 5, not used
Pin 6, 3.19v

So, the answer is yes. I see 3.19 volts DC between pins 1 and 6 on the DSMX transmitter module. Hope that helps. I tooks some photos and will update the article with this information. Thanks!
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HilldaFlyer on June 8, 2016
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cavityburn on June 8, 2016
I just rechecked the voltages, and the PPM pin has less than 1v. I had my VOM setting as auto and it stressed me out. I got it working though. Great article!
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jelle.sarita on January 3, 2017
Hello Hilldaflyer,

I'm really greatfull for this very clear discription, so thank you very much. But I'm just wondering; were are the capicitors ment for ?
Because in one of the scheme's they are not mentioned. So I made a testprint without the capacitors and noticed that everything was just working fine except that the elevator channel was reacting a little bit on the rudder channel.
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HilldaFlyer on January 3, 2017
But I'm just wondering; were are the capacitors ment for ?
Great question. I'm not an electrical engineer, so you'll probably not get a good answer from me. Capacitors hold a charge and are able to quickly dissipate the charge, so I can only imagine that their function is to stabilize the voltage coming in.
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jelle.sarita on January 4, 2017
Well that make sense, I think you only need this in case of using a bare voltage regulator like the TO-220.
In case of using a bec you don't need them.
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jelle.sarita on January 24, 2017
Hello Hilldaflyer, I did the spektrum mod following your instructions, which turned out really well, So thanks a lot for your clear explanation. I just wondering; should this also possible with a flysky RF module ? I Searched on the internet but couldn't find anyone who did this. It should be nice to also have the Flysky protocol on the Taranis, the receivers are really cheap and reliable at the same time.
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HilldaFlyer on January 24, 2017
I have not looked at a FlySky transmitter module, so I don't know what if the pinout is the same. If they are the same, I would imagine that you could make a FlySky module. Best of luck and let us know how it turns out.
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Nikolas on February 3, 2017
Wow! I'm interested to do the exact same thing, especially to get AFHDS 2a Tx.. Please inform me if you found any solution!
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