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Re: The Suspected Frsky GUID Issue

PostPosted: Fri Dec 03, 2010 5:29 am
by RCModelReviews
kneedrag wrote:Further to note not only would the system have to be on the same GUID for this to happen but on the same set of Freq channels.

Given that FrSky uses the entire band, both systems would be using the same "set" of frequencies. FrSky say that there are different hopping sequences but it seemed very much as if those sequences overlapped for significant periods of time -- hence the effective interaction "coming and going" over time when the systems were left turned on simultaneously.

I don't know how FrSky handle the creation of their hopping tables but it looks *very* much as if it's derived from a hash of the GUID -- in which case: same GUID = same frequencies (sooner or later).

Due to this being a large flyin and the Spectrum range was fairly full it would not have helped them finding a free spot in the band and would have compounded the issue.

The FrSky system does not appear to be adaptive so it won't make any difference how many other users there are on the band as to which frequencies it uses. In this regard, it's the same as FASST and most other FHSS systems (except Hitec's AFHSS system when in its "scan" mode.

Re: The Suspected Frsky GUID Issue

PostPosted: Fri Dec 03, 2010 8:33 am
by kneedrag
Corona would see the FrSky GUID and traffic as noise as each transmitter has there own protocol. Unless there was some freaky coincidence in the way the two systems transmit data I would doubt it. Would be the same for any other systems protocols they see each other as noise.

Roger wrote:Hey Rob / Bruce, I wonder if this issue was also affecting my Corona system at the weekend too? The little receiver in my Alula handlaunch went nuts for a while and wouldn't bind up properly - yet when I got it home there was nothing wrong with it... yet I had the same type of receiver in my Chucko and it flew all weekend with no problems - except from my terrible last landing! :(

Re: The Suspected Frsky GUID Issue

PostPosted: Fri Dec 03, 2010 10:53 am
by fanman
Makes me wonder why we went to 2.4GHz in the first place :-)

I hope FrSky have some good news as most of my fleet is on this brand. I've been trying to figure out what will be my next solid radio.... but looks like it'll be a while until manufacturers sort things out.

P.S...Sold my Spektrum gear recently, wasn't too fussed on it anyway.

Re: The Suspected Frsky GUID Issue

PostPosted: Fri Dec 03, 2010 1:07 pm
by lexmark
Hey Gentleman and any Ladies, please keep this active as I have recently ordered the FRSKY system and 6 extra receivers. Just when I think I am buying the most up to date system, a friend sends me this link. I hope I will not be sorry for this move. I will keep watching and appreciate any good solid input of tips and things that should be done. Thanks

Re: The Suspected Frsky GUID Issue

PostPosted: Fri Dec 03, 2010 7:29 pm
by RCModelReviews
lexmark wrote:Hey Gentleman and any Ladies, please keep this active as I have recently ordered the FRSKY system and 6 extra receivers. Just when I think I am buying the most up to date system, a friend sends me this link. I hope I will not be sorry for this move. I will keep watching and appreciate any good solid input of tips and things that should be done. Thanks

In every respect to date, the FrSky system has shown itself to be trusty and dependable. I think (unless there are other reports to the contrary), this is a very isolated event.

However, I will be publishing any information that comes to hand.

Re: The Suspected Frsky GUID Issue

PostPosted: Fri Dec 03, 2010 8:59 pm
by Beton
Hello Mister Bruce,

I Think it's good to warn people for this kind of problems.
That's the reason that I am surprised that there is no warning for the same problems with the Corona DSSS system.
In the Netherlands we have problems with this system.
Different people have informed you about this including videos and information from Corona itself.
See the two links below.

viewtopic.php?f=47&t=29&start=30

viewtopic.php?f=44&t=473

I think this information is enough to give a big warning to Corona users just as you did for FrSky users.

Kind regards,

Beton

Re: The Suspected Frsky GUID Issue

PostPosted: Fri Dec 03, 2010 9:15 pm
by jab
fanman wrote:Makes me wonder why we went to 2.4GHz in the first place :-)


I agree that a 16bit pseudo random GUID is bad, bordering on terrible design. But even so it still is MUCH safer then the old 35/72khz systems.

Re: The Suspected Frsky GUID Issue

PostPosted: Sat Dec 04, 2010 2:06 am
by Fulg
Wow. As a programmer, I can't believe that they think 16 bits is sufficient for this purpose. GUID stands for Globally Unique IDentifier; this certainly isn't a unique identifier in any way for a consumer product. I'm pretty sure FrSky intended to sell more than 65536 transmitters! I certainly wouldn't trust any model to this design...

While I don't like paying more for Futaba 2.4GHz radio gear, it's the kind of thing that makes me glad that I do. Then again, people used to say similar things about Spektrum too before the DSM2 issues came up (fingers crossed) ;)

And yes, I realize Futaba has had non-unique GUID problems in the past, but the problem was fixable and not caused by a serious design flaw.

Cheers,
Ben.

Re: The Suspected Frsky GUID Issue

PostPosted: Sat Dec 04, 2010 4:52 am
by Icarus
On the matter of distance of the Tx when binding, Spektrum calls for 3 feet minimum (and no big metal things like toolboxes nearby). Fly Dream mentions the issue but as I recall talks about not closer than 10cm.

Re: The Suspected Frsky GUID Issue

PostPosted: Sat Dec 04, 2010 11:36 am
by RobC
one unique and isolated incident and suddenly the system is pants? I think not. I'll happily carry on using FrSky just as I have done since it first arrived in the UK. I can honestly say I've never had an issue with any of the 3 systems used to date - 1 way and both v1 and v2 2-way. If I fly somewhere with other FrSky users on 1-way, I'll just cross check with them before flying - simple!