Independent tests prove lack of frequency hopping with XPS

[KrisW]

	Quote: Originally Posted by BaldEagel
	Trouble with that is if we all did it the pages would only have a few posts each on them. Mike

well, if you really want to save ALL that space, you can always choose a "1" font. . . . .

Iimagine all the bandwidth, memory, and space on your monitor you'd save. . .

[JimC-MD]

	Quote: Originally Posted by KrisW
	well, if you really want to save ALL that space, you can always choose a "1" font. . . . . Iimagine all the bandwidth, memory, and space on your monitor you'd save. . .

GreAt IdeA!!!

[Cherokee Jim]

Hello All,

"Firstly Cherokee Jim Please reduce the size of your font, you have been asked before not to shout."


Sorry about that - I am not shouting - just trying to make things easier for others to read.
If I shouted I would use 7 RED font!

Happy Flying,
Cherokee Jim Mahoney

[dick hanson]

	Quote: Originally Posted by Cherokee Jim
	Hello All, "Firstly Cherokee Jim Please reduce the size of your font, you have been asked before not to shout." Sorry about that - I am not shouting - just trying to make things easier for others to read. If I shouted I would use7 RED font! Happy Flying, Cherokee Jim Mahoney

I would prefer that the site accepted only a "standardized type"

[Gordito Volador]

	Quote: Originally Posted by Cherokee Jim
	JD needs a glitch counter like Spektrum so we can see whats happening in the air - signal loss, frame misses, low voltage.

Makes me wonder why JD hasn't done it yet, or has he? Just not selling it, he wouldn't want too much accurate test data out there. The XPS saga could have been put to rest a long time ago with just a few straight answers. However, JD thrives on the controversy, it is for sure free advertising.

Regards, Bill

[KrisW]

	Quote: Originally Posted by Gordito Volador
	Makes me wonder why JD hasn't done it yet, or has he? Just not selling it, he wouldn't want too much accurate test data out there. The XPS saga could have been put to rest a long time ago with just a few straight answers. However, JD thrives on the controversy, it is for sure free advertising. Regards, Bill

You can buy glitch counters from several vendors. Seems like a wise investment if you are going to be flying a system that does not carry the feature.

[KrisW]

	Quote: Originally Posted by dick hanson
	I would prefer that the site accepted only a "standardized type"

That would get boring, Dick. . next thing you know they'd require us to use good manners and spell checker as well. . .

[Daemon]

	Quote: Originally Posted by KrisW
	You can buy glitch counters from several vendors. Seems like a wise investment if you are going to be flying a system that does not carry the feature.

Connected to pretty much any 2.4Ghz system, a glitch counter would see nothing.
They're all packet based and will reject any malformed packet and
simply hold last position until the next valid packet, then jump to failsafe after some longer
interval interval of not receiving any valid packets (second or two or three.. etc).
When an analog PPM FM system glitches it sends garbage to the servo
which the counter can see. A servo connected to any of the 2.4Ghz systems won't
see garbage except following a boot/reboot. Counting failsafes won't really help (although there
are counters that can do that too) if the problem never lasts the full failsafe interval.

I could swear that JD said something about adding some other counters to
the latest firmware (reboot, lost packets, etc), but I can't find it now.
It's the sort of information that XPS would be uniquely positioned to display
in realtime to the user via the long overdue telemetry system.

ian

[XJet]

	Quote: Originally Posted by Daemon
	I could swear that JD said something about adding some other counters to the latest firmware (reboot, lost packets, etc), but I can't find it now. It's the sort of information that XPS would be uniquely positioned to display in realtime to the user via the long overdue telemetry system. ian

I think JD has pulled a whole bunch of his recent claims.

I went looking for the posting in which he said that his telemetry system could simultaneously log up to 120 users but that's gone.

Of course we know that a single telemetry receiver couldn't possibly do that -- and so does JD -- but it looked like a great claim. :-)

[KrisW]

	Quote: Originally Posted by Daemon
	Connected to pretty much any 2.4Ghz system, a glitch counter would see nothing. They're all packet based and will reject any malformed packet and simply hold last position until the next valid packet, then jump to failsafe after some longer interval interval of not receiving any valid packets (second or two or three.. etc). When an analog PPM FM system glitches it sends garbage to the servo which the counter can see. A servo connected to any of the 2.4Ghz systems won't see garbage except following a boot/reboot. Counting failsafes won't really help (although there are counters that can do that too) if the problem never lasts the full failsafe interval. I could swear that JD said something about adding some other counters to the latest firmware (reboot, lost packets, etc), but I can't find it now. It's the sort of information that XPS would be uniquely positioned to display in realtime to the user via the long overdue telemetry system. ian

Post #1000 ! ! ! YAYYYYYYYYYYYYYYYYYYYYYYYY!!!!!!!!!!!!!!

ON a more serious note .. that SUX Daemon. It might be better for how the system performs on 2.4 (due to the very high frequency and refresh rate)but it doesn't do us modelers much good.

Given the Xbeepro's characteristics. . is it even possible to add such features to it?

[Cherokee Jim]

Yep the traditional glitch counter for PPM systems are based on a missing pulse detector and a counter, JD would need to program his receiver or add another micro to listen in on whats happening with the main micro and count bad frames, detect low signal levels, monitor battery voltage, etc.

If I were designing a radio I would have to design and prefect this peice of test equipment first before the radio itself.

Does anyone know what system XPS and Spektrum are using , CDMA, etc.?

When you look at a spectrum analyzer you see that it is generating RF, But you need to be able to decode and read the packets of information to really know anything. Instruments that do this are even more expensive than just a good old Spectrum analyzer.

Happy Flying,
Cherokee Jim

[BZFrank]

	Quote: Originally Posted by Cherokee Jim
	Does anyone know what system XPS and Spektrum are using , CDMA, etc.?

They did not design the radio - neither Spektrum nor XPS, both use standard modules that comes with their own full radio implementation:

For Spektrum you may be able to trace into the transmission with a Unigen Juno Dev Kit, it contains a packet analyser tool. Spektrum uses the Unigen 'Juno' WirelessUSB module.

For XPS (using Digi/Maxstream XBee Pro) you can use most any IEEE 802.15.4 packet analyser. Its protocol is IEEE 802.15.4. That was successful tried by many parties now (me included).

[cadconversions]

	Quote: Originally Posted by BaldEagel
	Trouble with that is if we all did it the pages would only have a few posts each on them. Mike

Sorry, pages are based on the number of post not the length of the post or the size of the font.

[Cherokee Jim]

Thanks for the info BZFrank!

Happy Flying,
Cherokee Jim

[sweetpea]

	Quote: Originally Posted by XJet
	I think JD has pulled a whole bunch of his recent claims. I went looking for the posting in which he said that his telemetry system could simultaneously log up to 120 users but that's gone. Of course we know that a single telemetry receiver couldn't possibly do that -- and so does JD -- but it looked like a great claim. :-)

Alot of that information was lost because of the extremely negative posts following information like that. So it was XPS forums and they deleted the whole thread.

There is a difference from constructive critiques of the system and then just plain bashing.

I prefer to use the constructive form in hopes the system may have improvements down the road.