Want true DSMX in your Taranis?

makattack

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At this point, I would question the cost effectiveness of making a DIY module, especially if you don't already have the parts for it. These days, you can get the DIY Multi Protocol Modules for about $40 and they support a whole range of protocols, especially if you are using OpenTX.
 

HilldaFlyer

Well-known member
I would agree with David. Multi Protocol Module would be the way I would go, certainly would be the way I would go if doing this project today. However, if you like to tinker.... go for it. I like a good tinker.
 

varg

Build cheap, crash cheap
If the modules are that good I'll go with that, I love a good tinker, but I don't have loads of free time.
 

makattack

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Just a word of warning. Those multiprotocol modules DO NOT eliminate the need to tinker. You just end up tinkering with software instead of hardware.
 

HilldaFlyer

Well-known member
Just a word of warning. Those multiprotocol modules DO NOT eliminate the need to tinker. You just end up tinkering with software instead of hardware.

David - do you have one of these multi protocol modules? I don't so how much software tinkering is there?
 

makattack

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David - do you have one of these multi protocol modules? I don't so how much software tinkering is there?

I do, I have the irangex STM32 v1 multiprotocol module (no switches/LEDs) -- it's really only suitable for OpenTX use with a serial connection (which suits my X9D+) as there is no pot/switch to select protocols. It needs to be done through OpenTX 2.2+

That's part of what I was referring to by software configuration. That part isn't any different from any TX setup, and would have to be done with the DIY Spektrum module as well.

The additional software comes, depending on which version of the multimodule you end up purchasing. If you purchase a sufficiently new module, especially one with a USB port, the software that drives the multimodule itself may be sufficiently new, or easily upgradable. My multimodule requires me to open it up, connect a FTDI interface to it, and flash new software from Arduino IDE pulling from the latest github repository:

https://github.com/pascallanger/DIY-Multiprotocol-TX-Module

As you can see from the commit history, Pascal makes fairly frequent updates. He's fixed bugs and made improvements in it that I deemed sufficiently worthwhile for me to upgrade my module with on a fairly frequent basis. I last updated mine about 2 months ago, but you can see that he's had updates from 10 days ago. They were mostly documentation updates, so I don't need to take it apart to reflash for those.

The newer STM32 modules with the pot/selector and USB interface would be well worth the slightly higher cost, IMHO. If you have a OpenTX 2.2 Taranis (for SBUS in the module bay), you don't need the pot, as all the protocols are selected by the TX menus, but the USB is handy for installing new software without the FTDI bit.

Hope that helps.
 

varg

Build cheap, crash cheap
I got my IRX4+ the other day and slapped it in. Bound up to my nano CPS on the first try in serial DSMX 22ms mode but I can't for the life of me get the config to work properly. I can fly it in stability mode but it refuses to switch to 3D mode, and the channels were all mixed up vs an available .eepe file for a nano CPS on taranis. It's really quite frustrating and I can't seem to find any info on any related problems. This is my config file: https://drive.google.com/open?id=1Vd33yqUKhbgaajCNth1Sbi_yCW_z-x0q

Any ideas?
 

tamuct01

Well-known member
I just got one of the IRX4 modules myself and tried to get it working initially with an Orange Rx receiver in a car. Two channels - what could be simpler? I quickly found that throttle and steering were not on the correct channels from my existing module. I found by searching that the IRX4 module REALLY wants the channel order to be AETR. I had setup my Taranis to be TAER and all my models are setup in this fashion as well. After swapping around in the model file to put the order AETR and the steering on CH1 and throttle on CH3 it worked! I proceeded to swap all the channel orders around in my other Spektrum models to AETR and confirmed that they worked properly. Don't try to switch where you plug in the servos on the Rx - use the labeled order (which is probably TAER). I've successfully tested my Inductrix FPV, Blade MSRx, Blade Nano CPX, Blade 180CFX, and a couple models with Orange receivers. Good luck!
 

varg

Build cheap, crash cheap
Thanks. That confirms that the issue is with the module's channel order instead of the CPS flight controller. I read in a couple of places that I must limit the channels to 80% on the outputs page so I did. Did you have to do that or is it internal to the IRX4?

Now to figure out why the throttle on channel 6 has no effect on head speed whatsoever and why the mode selection on channel 5 doesn't work. If I switch to 3D mode with an offset I found by trial and error, changing values until the FC LED went from blue to red, it will spin up as if in idle up with the collective stick down, but as soon as I cross over the halfway point with the collective stick it goes back to stability mode (blue LED) and the head speed drops.

I used info from this link https://www.helifreak.com/showthread.php?t=724927 to try and figure out flight mode switching and this is the eepe file that I could not use due to channel order. https://rcsettings.com/index.php/viewdownload/4-helicopters/244-blade-nano-cps

(edit)

No wonder I couldn't consistently get it to switch to 3D mode, it wasn't responding consistently because it's dead. Apparently having the transmitter set up wrong can kill the board, even if you haven't done anything bad to it (stalled servos, bad crash, stalled motor), what a piece of junk! I have been wasting my time.

It powers up and responds to some but not all controls with the low-quality RTF transmitter it came with, it flew with this transmitter before but the sticks are horrible so I wanted to get it flying with the taranis ASAP.
 
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makattack

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varg, sounds like you're close to sorting it all out. Just in case you haven't already discovered it, but the best and most direct to the source (developer) documentation is linked to here:

https://github.com/pascallanger/DIY-Multiprotocol-TX-Module

The developer is also quite active on the rcgroups forum linked to from that github wiki page. I would also suggest checking to see what version of the software on your module (you can find it from the OpenTX model setup where you select the protocol) and see if there may be updates that are relevant to you. I know a fairly recent change (within a few months) was to update the Spektrum channel limits to by default mirror the Spektrum TX's.

Here are the commits for it on 9 Jan with the version number at 1.2.0.11:
https://github.com/pascallanger/DIY...mits/6fa3b8597f5fb5d641cfbb87fb2b72a4a86c430c
 

varg

Build cheap, crash cheap
A little closer to sorting it out than I was a week ago. I assumed the board had broken or was defective so I ordered another one, and it is doing the exact same thing as the board I replaced with the transmitter the helicopter came with. I'm baffled. I figured out a working model for the CPS in the Taranis though
1- Ail
2- Ele
3- Throttle
4- Yaw
5- Mode
6- Collective
So at least I can fly it now. Once I get the model exactly how I want it I'm going to post the config file in case anyone else ever wants to fly a Nano CPS with a Taranis and IRX4+
 
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OttoPilot

Member
So, looking into this as I would like to run some Horizon BNF models without buying yet another TX.

How's the latency running that IRX4+ module? Anything noticeable?
 

makattack

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I had lost track of this thread. I also have a NanoCPS, so I'll try setting it up with my iRangeX multimodule and see if I can get it working, varg.

OttoPilot, I haven't noticed any latency issues based on my flying small fixed wing planes (Horizon UMX planes), some toy quads (Dromida) and one micro Heli: Axe100 CP (no longer in production). I'll have to fly it more to check, but those models fly similar if not better to the DX6i or Tactic radios that I used to use with those models. Part of that might just be the better gimbals I have on the Taranis X9D+ (I have the hall effect gimbals) with increased resolution/accuracy that they provide over the other TX's.
 

donalson

Active member
well I got the last of my parts in the mail today and built it... got it all working nicely and dialed in on my 3 BNF planes... I came across a nice package deal that came with a dx4e (and a dx6 which I sold)... the most difficult thing like others said was desoldering the module. I sure wish I had access to the soldering station I had back in college... that solder sucker made quick work of desoldering things haha... but some paitence with some wick got it loose, I put a blade though the foam insulator two sided tape and off it came... I built all 3 of them as long as I was building the one... I need to test the others with my module then I'll try and sell them.

I had thought about one of the 4 in one modules but know for a fact that this works and would be easily doable... I am a little dissapointed that I don't have at least RSSI as far as I can tell but I only plan to use it with BNF and some park fliers (being that I can get decent inexpensive RX a good bit cheaper than I can frsky Rx).


on a side note... I'm going to need to get a module at some point for my "spare" (aka my kids) fs th9x... assuming I can ever get open TX installed on it...
has anyone compared the range in the 4 in 1 modules vs the d4xe module or on the taranis?
 

rockyboy

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Great to hear your success on this! I haven't done any range comparisons between my DIY module and other radio boards, but I also haven't had any range problems flying to the edge of my comfortable sight lines with it.
 

donalson

Active member
Great to hear your success on this! I haven't done any range comparisons between my DIY module and other radio boards, but I also haven't had any range problems flying to the edge of my comfortable sight lines with it.

Thanks... I'll likely pick one up here in not too long for my spare/kids flysky th9x as it needs a module other than the FS module anyway lol...
 

donalson

Active member
so quick question... how do I set failsafe for spektrum Rx? the lemon rx rx I have coming have a button, but for satelites and others that don't have failsafe buttons how can I set failsafe?
 

rockyboy

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so quick question... how do I set failsafe for spektrum Rx? the lemon rx rx I have coming have a button, but for satelites and others that don't have failsafe buttons how can I set failsafe?

I think most of them set fail safe at the values being transmitted when the receiver is bound, but I'd recommend trying with the props off for sure :D