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Want true DSMX in your Taranis?

finnen

Senior Member
#81
I believe the module is limited to 6 channels max (not sure). If it is, it shouldn't be an issue to use just one channel for both flight modes and the beeper if you are using a Taranis and cleanflight/betaflight.
 

HawkMan

Senior Member
#82
Hi there, I am interested in your parts to build one please. By the way your write up is awesome!!! Is it still limited to 6 channels? I find channel 7 very useful on many of my mini quads to make the beeper beep to help me find them in a crash.

How much for a set of parts plus USPS shipping to 44039?
Your mini quads on a taranis should use a frsky receiver though.
 

pressalltheknobs

Posted a thousand or more times
#83
I believe the module is limited to 6 channels max (not sure). If it is, it shouldn't be an issue to use just one channel for both flight modes and the beeper if you are using a Taranis and cleanflight/betaflight.
The DIY module is designed to use a TX module harvested from a DX4e, DX5e or Dx6i. These share the same 6 channel TX module. To be clear the "parts" on offer are essentially just a voltage regulator, some surrounds and connectors and a PCB. They do not include that DX TX module. You will have to harvest it yourself from your own DX4e, DX5e or Dx6i. Not sure why you would from a DX6i unless it was otherwise unusable.

I agree with Hawkman that if you have a Taranis you should use FrySky Rxs out of preference. The ability to use Spektrum Rxs is nice but it's limited. While it's useful if you have a lot of Spektrum gear, the primary reason to make one of these modules is so you can to fly Spektrum BNFs with the convenience of model memory - why it's worth lobotomizing a DX4e/DX5e rather than just using it. It is not really intended as a full replacement for a Spektrum TX, more as something that makes the Taranis more useful.

That said... I believe OpenTX supports the DSM* DIY module by sending a DSM (aka SpekSat) data stream to the module and that OpenTX can support sending more channels. However I don't know if the channel number is limited in the software and you have to buid your own version of OpenTX to have it send more channels. There is no documentation I have found that indicates modules from other better endowed Spektrum Txs can or can't work but they are generally not cheap enough to justify experimenting. There is one unsubstantiated comment that indicates someone may have got a 12 channel to work at one time. It is likely that you cannot do this trick with newer Spektrum TXs since the TX module is probably not a separable thing you can remove easily.
 
#84
So I have a dx5 that I bought at the swap meet so I would have a cheap and easy buddy box. Will it still work as a buddy box if I pirate the module out of it? Maybe work on a computer sim? Thanks
 

pressalltheknobs

Posted a thousand or more times
#85
So I have a dx5 that I bought at the swap meet so I would have a cheap and easy buddy box. Will it still work as a buddy box if I pirate the module out of it? Maybe work on a computer sim? Thanks
Supposedly yes to both of those. I haven't done it yet so I cannot personally confirm that but it makes sense. Trainer and Sim only require the PPM out and that is separate from the TX module.

You can also solder a connector into the DX5e so you can plug the TX module back into it if you needed it to be a transmitter again for some reason.
 
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tekyguy

Junior Member
#86
Your mini quads on a taranis should use a frsky receiver though.
But they all already have a DSMX Satellite receiver on them. I don't want to replace them all. All new builds will have an frsky receiver moving forward.

My Transmitter up to this point has been an older DX7 DSM2 only model. I upgraded to the Taranis for many reasons, but getting DSMX out of it for my existing models including some spektrum BNFs is icing on the cake.
 
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pressalltheknobs

Posted a thousand or more times
#87
But they all already have a DSMX Satellite receiver on them. I don't want to replace them all. All new builds will have an frsky receiver moving forward.

My Transmitter up to this point has been an older DX7 DSM2 only model. I upgraded to the Taranis for many reasons, but getting DSMX out of it for my existing models including some spektrum BNFs is icing on the cake.
Fair enough but there's not much out there on anyone making one of these JR style module from a DX7 DSM2 TX. I've searched around a couple of times. So probably you are on your own if you want to do that. It might just work but it might be quite different.
 

pressalltheknobs

Posted a thousand or more times
#88
Ok, sort of the antithesis of the thread title but I came across this today.... Another module option. Bit pricey. No DSMX but DSM2 and some other things in case you have DEVO envy. Seems it may not work with some receivers though....probably just a frustrating to use as the new Orange modules. Anyway, just pointing it out in case it is of interest.

http://www.hobbyking.com/hobbyking/...otocol_Spectrum_System_MTSS_Mul_JR_Style.html
 

Craftydan

Hostage Taker of Quads
Staff member
Moderator
Mentor
#90
Would anyone be interested in one of these modules that will only work with DSMX, no DSM2 support?
Wait . . . that's an interesting trick. DSMX is supposed to be backwards compatible to DSM2. What are you using to build modules that don't revert back to dual channel, non-hopping?
 
#91
I was just as surprised Dan. It's a module out of a DX4, and it's marked as a EU spec module. Since the DX4 is only meant to be used with a couple specific models, I'm not totally surprised that it's set up this way. I run a mix of both protocols for receivers, so this really doesn't do me a ton of good.
 

HilldaFlyer

Well-known member
#92
That's too bad, and weird, isn't it? The module that I extracted from the DX4e Tx has the label:
19.55dBm DX5e
Horizon Hobby Inc.

And it is DSMX compatible.
DSMX.jpg
 

MrClean

Active member
#93
There is a mention of the European model serial numbers with issues higher in this thread. Had to check on the one I was buying to make sure everything was okiepadokie. So some will work and some will not.

IF you get one and it is of the affected serial numbered transmitters send it to Spektrum and they'll flash it.

Uhhhhh, do this before you yank the module out, k?
 
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pressalltheknobs

Posted a thousand or more times
#94
Its not that weird. DSM2 is not longer legal for new sales in the EU as of last year 2015. I'm sure Spektrum were anticipating that for some time. The DX4e, DX5e and DX6i supposedly all shared the same 6CH module but there may be variations in the firmware used.

DSMX uses the same binary signalling as DSM2 but it uses a different RF channel management scheme. The DSM* protocol and variant used is specified in the bind message. I very much doubt that both channel management schemes are in operation at the same time so, assuming that, DSMX is technically not backward compatible with DSM2, but DSMX equipped TXs and RXs have been able to do either. Except now in the EU they can't!

I'm unclear how the transmitter decides that the Receiver is DSMX and not DSM2. There are a number of variants of each. I think there is a short range RF transmitted ACK from the RX, a kind of nacent telemetry signal, that indicates the RX is DSMX or DSM2. This discussion about binding satellite receivers supports that notion.

OpenTX sends a DSM binary stream to the DIY module for the channel "transfer" packets. It does not use PPM. I'm not sure how binding works in this case. It is possible it is all done by the Spektrum TX module but it has to be initiated by OpenTX - there is a soft BIND "button" and a choice between LP45, DSM2 and DSMX. LP45 is the low power "France" DSM2 mode. DSM2 and DSMX are presumably their respective modes. Possibly the DSMX selection does not implement fall back binding to DSM2. Possibly they all use the default lowest common denominator variant and just assume the RX can speak it without bothering to listen for an ACK. Have to poke around in OpenTX code to find out.
 
#95
Yeah, I totally had no idea about the EU spec stuff when I bought the radio I cannibalized the transmitter module out of. Not sure what I'm going to do with the completed module now, DSMX only isn't too useful for me.
 

MrClean

Active member
#97
And if he has planes that have DSM2s in them, is he just supposed to go out and buy a whole bunch more DSMX rx's. I haven't flown 72Mhz in 5 years but I still have 4 receivers that I just took out of planes.
 

rockyboy

Skill Collector
Mentor
#98
Yeah, I totally had no idea about the EU spec stuff when I bought the radio I cannibalized the transmitter module out of. Not sure what I'm going to do with the completed module now, DSMX only isn't too useful for me.
I had the exact same problem and ended up building a second module. And then the second module is only happy with DSM2. So now I have one module for each of the Spektrum versions. With model matching, it's still better than using the OrangeRX module - I was very happy to sell it off.
 
#99
I have a mix of genuine Spektrum DSMX stuff and Orange/Lemon DSM2 receivers as well as some FrSky stuff. I do have another module that works just fine, this was going to be a spare but I may just sell it as-is.
 

HawkMan

Senior Member
And if he has planes that have DSM2s in them, is he just supposed to go out and buy a whole bunch more DSMX rx's. I haven't flown 72Mhz in 5 years but I still have 4 receivers that I just took out of planes.
Wasn't talking about him though, more like for my own planes if I decided to get/make a model if I wuld really need a DSM2 capable module for my red UMX cub and my sukhoi 26mm (which hs a broken receiver anyway and will probably be replaced with a frsky one to see how bad I fly sans gyro)