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Frsky compatibility

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03 Mar 2014 01:13 #21117 by stevecox
Replied by stevecox on topic Frsky compatibility
This is REALLY exciting & going to be an incredible jump for me in Deviation as I have a bunch of frysky receivers I would then be able to use with the telemetry on my Devo's. Once stable I think this is a MAJOR jump, really MAJOR jump for Deviation, you guys really should take credit for the amazing work, time and effort, it is TREMENDOUSLY appreciated!
Adelaide

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03 Mar 2014 01:33 - 03 Mar 2014 01:39 #21118 by PhracturedBlue
Replied by PhracturedBlue on topic Frsky compatibility

FriedSky wrote: 1. The reset command has a delay of > 50us after being sent. ... On RC groups people have come across problems with the reset but not realised what was happening. If in doubt, read some known data out of the cc2500 before continuing.

should have read this closer...oh well

FriedSky wrote: 2. The seed should be a "u32".

You are right

FriedSky wrote: So far i think the relationship between Tx ID and the hopping table channels is simply the TX ID modulo division 5. The 50 channels in the hopping table being spaced apart by 5 with the remainder added as an offset. I'm guessing that any selection 50 channels could be used.

This is what I wrote in the Frsky docs:

PhracturedBlue wrote: The binding packets define a list of 50 channels that will
be used during data transmission. At least for some
transmitters, these channels are sequential with a uniform spacing of 5,
but this is likely not strictly required. Channel values of 0 and 1 are
apparently invalid. From observed data, the 1st channel in the sequence
was 6.

which seems to indicate it doesn't much matter how you choose the 50 channel sequence.

FriedSky wrote: I'm probably going to have a go at automating the process of finding the connection between crc start value and Tx ID for the data packets.
Listening to the spi on the rx side wont work because the crc is generated and checked in software.


I'm looking at this now, but I don't see the issue you do. So far I've tried many different values, and my V8R7-II works fine with any txid I use (after binding) without recalculating the crc initialization
Last edit: 03 Mar 2014 01:39 by PhracturedBlue.

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03 Mar 2014 01:44 - 03 Mar 2014 01:49 #21119 by PhracturedBlue
Replied by PhracturedBlue on topic Frsky compatibility
Apparently my V8R7-II ignores the CRC value. I threw an arbitrary crc in there, and it still works ok. So it doesn't look like there is much I can do to debug this unless I can obtain a 'V8'receiver which honors the CRC.

FriedSky:
What receiver are you using?
Last edit: 03 Mar 2014 01:49 by PhracturedBlue.

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03 Mar 2014 02:06 - 03 Mar 2014 02:18 #21122 by midelic
Replied by midelic on topic Frsky compatibility
If I understand correctly in TI data said before reset you must toggle CS pin and wait min 40us till strobe reset command..this is part of CC2500 reset routine..and in spi sample data of both FrskyTx(DHT) and RX(RXD8RSP) the wait after reset is 43us
Last edit: 03 Mar 2014 02:18 by midelic.

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03 Mar 2014 02:21 #21123 by PhracturedBlue
Replied by PhracturedBlue on topic Frsky compatibility
Thanks to th9xr, we have a winner:
reveng -w 8 -s 00000e 0001d7 0002bb 000362 1257a6 12587d 1259a4 1e2d89 1e2ee5 1e2f3c 32101f 3fff45
width=8  poly=0xc1  init=0x6b  refin=true  refout=true  xorout=0x00  check=0xc6  name=(none)

so polynomial is 0xc1, init is 6b and it is a little-endian CRC, the code I used in the mlink protocol should work here:
www.deviationtx.com/forum/protocol-devel...s-crc?start=20#20793

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03 Mar 2014 02:23 #21125 by PhracturedBlue
Replied by PhracturedBlue on topic Frsky compatibility
there is a power-on-reset on the cc2500, so I don't think you should need to go through the reset procedure. At least my modules so fatr have not needed it.

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03 Mar 2014 03:21 #21126 by PhracturedBlue
Replied by PhracturedBlue on topic Frsky compatibility
I checked in the frsky-v8 code to enable txid selection. I've verified via printf that it works, and it works fine with my V8R7-II, but that is about all I can test with it.
I am also unsure of the servo range on the v8 protocol. Will need to do some testing to find the proper range.

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03 Mar 2014 04:29 - 03 Mar 2014 04:30 #21128 by midelic
Replied by midelic on topic Frsky compatibility
Not sure you don't have already or it is what you are looking for.
Attachments:
Last edit: 03 Mar 2014 04:30 by midelic.

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03 Mar 2014 05:37 - 03 Mar 2014 10:51 #21129 by vlad_vy
Replied by vlad_vy on topic Frsky compatibility
FrSky say the PPM ranges from 800*1.5(1200) to 2200*1.5(3300) (the 12 bit data is from 1200 (800uS) to 3300 (2200uS)).

It seems 0x8CB is center value.

PXX protocol for FrSky modules

File Attachment:

File Name: protocol.pdf
File Size:141 KB
Attachments:
Last edit: 03 Mar 2014 10:51 by vlad_vy.

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03 Mar 2014 11:35 - 03 Mar 2014 11:50 #21134 by FriedSky
Replied by FriedSky on topic Frsky compatibility

FriedSky wrote: I'm probably going to have a go at automating the process of finding the connection between crc start value and Tx ID for the data packets.
Listening to the spi on the rx side wont work because the crc is generated and checked in software.

I'm looking at this now, but I don't see the issue you do. So far I've tried many different values, and my V8R7-II works fine with any txid I use (after binding) without recalculating the crc initialization


Congratulations PhracturedBlue, Your on a roll now !.
I was beginning to think it was only Me that had the misfortune to hit every possible problem.

Re: CRC Start values
I did my initial testing with a V8R4 ... probably one of the early ones. I was convinced the CRC start value changed with TXID. I also have a V8R7 or something like that. I must go back and check.
Like i said, my code for AVR was a copy of your earlier work and maybe i introduced a bug / typo.

Have You sussed out the 3 data packet types yet ? From memory you can get away with sending 0x0F and 0xF0, 0x00 not used ?.

Regards, Rick.
Last edit: 03 Mar 2014 11:50 by FriedSky.

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03 Mar 2014 12:33 - 03 Mar 2014 13:00 #21137 by FriedSky
Replied by FriedSky on topic Frsky compatibility

PhracturedBlue wrote: there is a power-on-reset on the cc2500, so I don't think you should need to go through the reset procedure. At least my modules so far have not needed it.


I've lost count of the times i've updated firmware on a board and left the support chips in their previous state ... then went looking for a bUg that wasn't. NRF24L01+ was good for that.
Last edit: 03 Mar 2014 13:00 by FriedSky.

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06 Mar 2014 21:28 #21307 by Hexperience
Replied by Hexperience on topic Frsky compatibility
Hi All, I have a couple of CC2500 modules. Is the currently checked in code ready for testing? I have a few D series RX's.
There are 10 types of people in this world. Those that understand binary and those that don't.

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06 Mar 2014 22:50 #21310 by PhracturedBlue
Replied by PhracturedBlue on topic Frsky compatibility
yes, the current code is good enough for testing. Mostly just binding and servo motors. I wouldn't fly with it yet.
If you want to use telemetry, you should wire:
PA_EN to GDO0
LNA_EN to GDO2

If you have already wired PA_EN to 3.3V and LNA_EN to GND, that is ok too, but you can't receive telemetry that way.

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07 Mar 2014 02:09 #21321 by Hexperience
Replied by Hexperience on topic Frsky compatibility
I haven't installed it yet, so I'll give it a go and try to get telemetry as well.
There are 10 types of people in this world. Those that understand binary and those that don't.

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21 Mar 2014 21:23 - 21 Mar 2014 21:25 #21712 by Hexperience
Replied by Hexperience on topic Frsky compatibility

PhracturedBlue wrote: yes, the current code is good enough for testing. Mostly just binding and servo motors. I wouldn't fly with it yet.
If you want to use telemetry, you should wire:
PA_EN to GDO0
LNA_EN to GDO2

If you have already wired PA_EN to 3.3V and LNA_EN to GND, that is ok too, but you can't receive telemetry that way.


Sorry, I'm not the best inside the radios.

I have installed a NRF24L01+ for SLT and it seems to be working fine.

I have both the XL2500 and the Ali Express CC2500. Should I use one over the other? The XL2500 is a little easier for me because I bought a wire wrap tool.

I will follow the same idea for the install of the 2500 module, obviously using TMS because TCS is already used. (or the other way around).

Is there a wiring diagram I could follow when installing this second module?

If I can't get it right, I'll just un-wrap the NRF24L01+ and only use the one extra module.

Cheers

PS. once I have it installed and working, is there anything I can do to help capture telemetry data?
There are 10 types of people in this world. Those that understand binary and those that don't.
Last edit: 21 Mar 2014 21:25 by Hexperience.

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22 Mar 2014 14:38 #21722 by Hexperience
Replied by Hexperience on topic Frsky compatibility
Bound to my D8R-II Plus!!
So far nothing back on the telemetry, but I can move some servos!!

WooHoo!
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22 Mar 2014 14:51 #21723 by SeByDocKy
Replied by SeByDocKy on topic Frsky compatibility

Hexperience wrote: Bound to my D8R-II Plus!!
So far nothing back on the telemetry, but I can move some servos!!

WooHoo!


How solid is the connexion ?

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22 Mar 2014 15:08 #21725 by Hexperience
Replied by Hexperience on topic Frsky compatibility
You mean as in range? 12 inches so far. :)

I haven't got the tx back together yet, :)
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22 Mar 2014 16:46 - 22 Mar 2014 16:47 #21729 by Hexperience
Replied by Hexperience on topic Frsky compatibility
Binds to my D6FR as well. I also tried the FAS-100 amp sensor, which connects to the D8R on the serial port. Still no telemetry at all. (I haven't read up on any of this yet, so telemetry might not be implemented yet.)

I do have the GDO's going to the correct places. The LNA and PA are only connected to the GDO's and not directly connected to 3.3v in anyway.
There are 10 types of people in this world. Those that understand binary and those that don't.
Last edit: 22 Mar 2014 16:47 by Hexperience.

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22 Mar 2014 23:31 #21739 by PhracturedBlue
Replied by PhracturedBlue on topic Frsky compatibility
Is there a specific issue you are experiencing, or just reporting that it is working so far. I'll work on telemetry after I track down the issues in my multi-module, it is not expected to work as yet.

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