CopterX CX-CT6C / CX-CR6C usable with deviation?

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01 Mar 2014 21:20 #21045 by jo-loom
Does anybody know whether the transmitter CX-CT6C and the receiver CX-CR6C from CopterX being part of RTF helicopter kits are compatibel to anything else?
The system is using FHSS.

I have been unable to find anything in the web. The predecessor model CT6B appears to be compatible to FlySky.

After solving above question the next point is: Does deviation support the right protocol for CopterC CX-CT6C / CX-CR6C (of course using the right additional HF module)?

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04 Mar 2014 20:43 #21199 by jo-loom
Lacking any feedback yet I like to add some more information:

The bundle consists of a low cost 6 channel transmitter with small LCD and the mating receiver being available as:

CopterX CX-CT6C
www.ehirobo.com/transmitters-receivers/t...x-cr6c-receiver.html
(approx. 60 USD incl. RX)

or as TURNIGY 6XS
www.hobbyking.com/hobbyking/store/__2497...eciever_Mode_2_.html
(approx. 50 USD incl. RX)

CopterX CX-CR6C
www.ehirobo.com/transmitters-receivers/r...hz-6ch-receiver.html
(approx. 20 USD)

or as TURNIGY XR7000
www.hobbyking.com/hobbyking/store/__2490...urnigy_4X_6X_TX.html
(approx. 10 USD)

The protocoll is defined as FHSS with GFSK modulation.
I have not been able to find any useful information in the internet telling something helpful regarding the used protocol.
Up so far it seems that the used protocol is not compatibel to anything known such as e. g. Flysky. Indeed some availble comments in the web are confirming lack of success to bind TX or RX to any other system.

As soon as I am back next week I will try to post some photos showing used RF modules in transmitter and receiver.

@PB:

The deviation supported model list is already listing 'CopterX RTF' - but without detailed information regarding protocol or implementation status. Is the protocol already known or analyzed?

Can I somehow help for the implementation e. g. by recording the initialisation SPI data stream or reverse-engineering the RF SPI interface PCB connections?

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04 Mar 2014 23:28 #21206 by victzh
The first thing you can do is to make a detailed photo of the radio board and put it somewhere with a link here (this forum reduces photo size to unusable, so don't just publish photo here). Then we'd know what RF chip it uses and how hard is the reversing of the protocol from the mechanical point of view - how hard is to solder to the RF chip.

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11 Mar 2014 19:13 - 11 Mar 2014 19:16 #21466 by jo-loom
Please find attached pictures showing component and bottom side of the CopterX CX-CT6C = Turnigy 6XS FHSS transmitter RF module (after removal of the metal shield case) and the CopterX CX-CR6C = Turnigy XR7000S receiver RF module.

Both modules are using the NRF24LE1G so the known 2.4 GHz transceiver chip in QFN32 package providing 15 generic I/O pins.
Neither on the transmitter side nor on the receiver board you'll find a separate microcontroller.

Probably these photos are already allowing the cracks to identify compatibility to any known or already analyzed application.

Due to the fact that I have already installed several of these receivers in helicopters where I haven't got sufficient packaging space for larger OrangeRX receivers I would highly appreciate if the protocol can be added to the list of deviation solutions.

@ Administrator:
Probably it will help to move this thread to the right forum location 'Protocol development' - sorry for having started it in the wrong place.

Please let me know if I can contribute further support information.
Attachments:
Last edit: 11 Mar 2014 19:16 by jo-loom.

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11 Mar 2014 19:19 #21467 by victzh
More or less hopeless. This system use integrated RF chip on both ends, so the protocol implementation is embedded in the chip itself and there is no way to trace SPI interaction between MCU and RF - there is none. All other cases use separate RF chip at least at one end. The only hope is to decode the protocol directly from air using SDR, but I have not mastered this technique yet.

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11 Mar 2014 19:27 #21468 by jo-loom
Thanks a lot for the quick reply - bad news...

I did hope that the printed labels on the receiver side (MOSI, MISO, ...) are somehow indicating that the internal NRF24LE1G SPI interface is visible.

Just to understand the operation principle:
Am I right that the transmitter module gets controlled by the transmitter main microcontroller via SPI but just by using "simple" commands while the protocol stuff sits inside the NRF24LE1G?

I got everything here such as logic analyzer so I can try to record some SPI data if it will help.

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11 Mar 2014 19:59 #21470 by victzh
It's even not necessarily SPI - TX module has 24 pins at least 13 of which are connected to nRF24LE1. And even if there were SPI, it's commands should not have any correlation with low level RF chip register accesses. So even if you trace this it will be absolutely useless for the purpose of programming this protocol into Deviation.

They mention that it uses 20 channels, can you check that it does not bind to HiSky? HiSky also uses 20 channels, uses similar module in transmitter with the same chip, and people usually are too lazy to invent something - they prefer to copy (or may be even license).

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11 Mar 2014 21:15 #21472 by jo-loom
Unfortunately I am not yet lucky owner of any DEVO transmitter or even luckier user of deviation. Hopefully this will change pretty soon, depending on Asian delivery times.

As soon as my playground becomes available I will try anything to take these receivers into operation based on already implemented protocols - what means using try and error binding for all given NRF24L01 protocols.

Up to now I have not found any positive indication in the web that this TX / RX pair connects to anything else. Assuming that at least the Turnigy version should have quite a remarkable sales volume there should be some experience like that. On the other hand I can not imagine that anybody implements a complete new / different protocol for such kind of rare bottom range device.

We'll see - I'll get back soon.

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11 Mar 2014 21:18 #21473 by PhracturedBlue
Replied by PhracturedBlue on topic CopterX CX-CT6C / CX-CR6C usable with deviation?
I have been getting better at working with my SDR. I've mostly been playing with 433MHz and 345MHz stuff (with an RTL-SDR) lately to learn the ropes. I got the down-converter I mentioned previously, but haven't yet installed it, so I'm still working with my (reasonably expensive) USRP unit when working on 2.4GHz.

Still, I probably have several months (or more) of working with known data before I'm comfortable enough to try to decode unknown data. If I ever get far enough that I can snoop the NRF24L01, I may grab one of these to try, but it is unlikelyto be anytime soon.

As far as the spreadsheet goes, I clarified the state of the CopterX protocol.

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11 Mar 2014 21:26 #21474 by jo-loom
Strange - something is giving me the feeling that if anybody will get the job managed successfully then it will be you . . . ;)

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12 Mar 2014 04:13 #21493 by victzh
@jo-loom - pity, I have a hunch (pictures of TX boards are so close). Do you have Arduino and nRF24L01 board? I happen to have V202 code for Arduino ;-) You can just check whether it binds or not.

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12 Mar 2014 20:42 #21510 by jo-loom
@victzh

Wow - sounds interesting and promising!
Yes, I got several different nRF24L01 PCBs and plenty different ATMEL AVR chips.
I also got a few Arduino boards (Nano) but I hate to work using Arduino development environment.
All projects I've done so far (RC model electronics up to 8 kB code size) I always implemented in assembler using ATMEL studio 4 and 6.

So for me the easiest would be if you tell me:
a) the required AVR chip
b) the needed pinning in between AVR port pins and RF module
c) the needed fuse settings
d) the needed external crystal frequency (if not the internal one gets used)
d) a HEX file for the specified controller

In this case I would do a manual wiring / proto assembly and a direct flash programming of the controller without Arduino bootloader stuff.

Is something like this possible for you?

(Attached just for orientation two impressions of typical micro modelling electronics I've done)
Attachments:

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12 Mar 2014 21:32 #21512 by victzh
@jo-loom, how do you know that CX-CR6C and Turnigy XR7000 is exactly the same? I did not find any mentions. If it is, I'd buy XR7000 just to make sure that it binds (or not) to HiSky.

Sorry for misleading last post - I did not mean V202, I meant HiSky, for which, unfortunately, I don't have Arduino code.

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12 Mar 2014 22:03 #21513 by jo-loom
@victzh

There is very little information in the web regarding CopterX CX-CT6C / CX-CR6C respectively Turnigy 6XS / Turnigy XR7000S.

Having browsed for hours even on Italian / Spanish / Portugese sites I found somewhere this hint.

One example is post 247 in:
www.rcgroups.com/forums/showthread.php?t=1871383&page=17

Myself I only validated the compatibility based on visual appearance of the case with antenna wire location and headers.
Due to the fact that both transmitters do look exactly the same I assume that there is no risk in assuming both identically looking receivers are also the same.

Attention: it is important to use XR7000S not XR7000 (!)

If acceptable for you I love to pay for the analysis receiver. Just let me know.

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09 Aug 2019 23:00 - 09 Aug 2019 23:16 #74850 by dpstudio
here are som picture of CX-CR6C tx
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Last edit: 09 Aug 2019 23:16 by dpstudio.

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