Want true DSMX in your Taranis?

JonasL

Member
Inspired by a blogpost by John Prikkel i built a true Spektrum DSMX JR-module for the FrSky Taranis.

This video shows how to build a true full-range Spektrum DSMX JR module for the FrSky Taranis.
It completely integrates with the Taranis interface for binding, model matching and so on.

PCB Circuit Board: https://oshpark.com/shared_projects/mQXHRTOA
Empty SPM6817 module. https://www.spektrumrc.com/Products/Default.aspx?ProdId=SPM6817
Source for genuine Spektrum DSMX module: a DX4e (cheapest) or DX5e(a little more money)
BOM and further documentation: http://johnprikkel.blogspot.dk/2014/07/jr-dsmx.html

 

HawkMan

Senior Member
I assume the module is the same regardless of transmitter and channel count? so this will give as many channels as the Taranis supports?

Also what's the benefit over the orangeRX dsmx module?

Btw Danish English sounds like Norwegian English, weird since you guys normally can't speak properly at all :p
 

JonasL

Member
I assume the module is the same regardless of transmitter and channel count? so this will give as many channels as the Taranis supports?

Also what's the benefit over the orangeRX dsmx module?
It will only handle 6 channels, but thats enough for most DSMX bind-and-flys :D

Btw Danish English sounds like Norwegian English, weird since you guys normally can't speak properly at all :p
Haha :p I'm very aware that it's not British english, American english or Australian english which are the three most heard on youtube, but I'm glad you're able to understand :)
As a Dane I completely disagree with the Danish English to Norwegian English comparison though :black_eyed:
 

JonasL

Member
Regarding the benefits over the OrangeRX module is to my understand the following:

- Fully integrated (range test and bind functions from the Taranis menu, not the button on the module)
- True model matching (Seperate IDs in the recievers, so you can't by accident choose a wrong model, just like the FrSky D16 protocol)
- IMHO better antenna placement, not sticking out the back, so Taranis is still able to lie down flat and rest on the metal-handle.
- Possibly less latency (the Taranis is "speaking native DSM" with the module, not being coded to PPM)
- Being a genuine Spektrum module possible has other benefits?
 

Balu

Lurker
Staff member
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Moderator
Awesome.

There's only one thing I don't like: An OrangeRX module just got delivered to my mailbox.
 

xuzme720

Dedicated foam bender
Mentor
Is this mod a change from a regular Spektrum module? I'm just wondering if the normal Spektrum module will do the same thing or if there is a difference in this board that allows direct communication with the Taranis?
 

xuzme720

Dedicated foam bender
Mentor
Oh, I wasn't aware that they didn't make their own protocol in their modules! Looks like I'm shopping for parts then! Well, after Christmas. No money left for hobby stuff right now.
 

xuzme720

Dedicated foam bender
Mentor
It seems so as on the blog, he states this:
Printed Circuit Board (PCB)

My circuit board is JR-DSMX on OSHPark. OSHPark requires a minimum order of three PCBs since they make the boards on-demand. The board uses through hole components for easier soldering. If you plan on using the module in a Turnigy 9X radio and may use the radio with a PC simulator cable, use a 1K resistor for R2. If you don't need this feature or have a Taranis radio use a short wire instead of the 1K resistor for R2.
 

Balu

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I have tried to build one now, but I can't get it to work with my Taranis.

I have used the 1k resistor for R2 and upgraded my Taranis to openTX 2.0.15. The radio module comes from an MLP4DSM.

In a new model on the Taranis I've disabled the internal RF module and set the external RF module to mode DSM2, DSMX - Channel Range: Ch1-6.

I'm trying to bind with a NanoQX micro-quad. To do so the NanoQX is powered up until the blue LED flashes rapidly. I then choose the "bind" function on the Taranis and wait a few chirps. But the NanoQX LED does not stop flashing as it should.

Any idea what might be wrong?
 

califrag

Senior Member
Hi Balu try taking off the 1k resistor and using just a small wire instead. I just finished building mine for Turnigy 9x and I believe the resistor is only necessary if you are using Turnigy 9x AND are planning to use the module with a PC simulator software.

Since I don't plan on using it with a simulator I just put a small wire instead (0k resistor) and my module is working perfectly. :)

I believe you could probably leave the 1K resistor wired in, then on the opposite side of the board just put the wire connector between the two poles. The signal should take path of least resistance and go across the 0K wire instead but it might be best to just remove the 1K resistor to be safe.

I was able to bind using this module to a LemonRx DSM2 satellite receiver using the spektrum1024 setting and spektrum_sat_bind =3 on CleanFlight CLI, but not sure how the NanoQX bind procedure works.
 

Balu

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I have built a 2nd module with a wire instead of the 1k resistor without luck.

It looks like their are different MLP4DSM modules available and not all work. My module flashes the red light for a microsecond when the Taranis is powered on, but that's it.

I'll see if I can get a DX4e on eBay for a few bucks to see if that module works - it'll be a full range module too unlike the MLP4DSM one.
 

califrag

Senior Member
Ah alright sorry to hear that didn't work either. I forgot to include that I used the module from an old dx5e.
 

EdGruberman

Junior Member
Jonas, Thank you for your video. It was very helpful ensuring I was doing all that I needed to be doing. I've got my own module setup now in my Taranis Plus working great with all my Blade helicopters and Spektrum receivers. If anyone here wants a chance to just get a working module, I built a second one since I had to buy more than one printed circuit board. http://www.ebay.com/itm/201320788225

Thank you, again!
 

narcolepticltd

I unbuild stuff regularly
I just found this hack (considering purchasing a Taranis), and was curious if a spektrum transmitter with more than 6 channels is used: A. will it work? and B. Will I still only have 6 channels or will I be able to pull 8?

Not the end of the world, just wondering if it's possible or if I should just stick to looking for a used dx4e or dx5e on ebay.
 

HawkMan

Senior Member
if you need more than 6 you should probably just get an orange module. it'll give you the full Taranis range.
 

narcolepticltd

I unbuild stuff regularly
if you need more than 6 you should probably just get an orange module. it'll give you the full Taranis range.

I'm ok with 6, but if I can get more from this hack using a transmitter with more channels it's something I'm considering. I'm more interested in the integration this provides compared to the orangerx