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Apr 19, 2016, 12:01 AM
Win=span\massXpractice+lu ck
webbsolution's Avatar
If we dumb Johns data down the details lean towards -

Auto Frame output spacing appears to be "questionable" if you are also using a third party FC one should not use that feature.

Failsafe will be unlikely to actually deploy unless you turn off your TX in flight...

Q% reports are questionably inaccurate - it could be a sync issue but the general lapse in functional feedback appears to really bring into question the functional value of such a pivotal Data point.

John - you have a sharp mind and an objective approach to technology that is refreshing and at the same time objective.

Thank you for your efforts.
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Apr 19, 2016, 03:28 AM
Registered User
Geoff_S's Avatar
Cravenjw - very nice work !

I had been thinking about buying some OpenLog devices and using them to simultaneously log the EX bus data at the rx and tx while doing range tests, but have too much else going on Looks like you might have done something similar.

Just a comment about the EX Bus jitter. The Jeti spec states that if the rx loses signal, it will not output any EX Bus data. I'm guessing that the large jitter you're seeing is actually this effect, and not really jitter ? I'll admit I have only quickly skimmed over your results....

Likewise, what failsafe setting did you have on the rx - was it meant to drive servo 1 to a fixed value ? The large variations in PWM intervals (which are suspiciously grouped around multiples of 10 ms, ie the period between outputs when set to 100 Hz) make sense if that servo failsafe was set to "Output OFF".

Perhaps I should just wait for your separate thread before asking more questions
Last edited by Geoff_S; Apr 19, 2016 at 04:56 AM.
Apr 19, 2016, 05:41 AM
AMA District VII AVP
PropsnWings's Avatar
Quote:
Originally Posted by thurmma
The only box I can find that I think is what I would need is $160. Do you know of something cheaper? If so, I would appreciate any info you have. I am new to the Jeti world and love the DS-14. I have added the modules that allow me to use the radio for what I need at a lot less than a DS-16 would have cost me. Thank you Jeti for offering an alternative.
Quote:
Originally Posted by ltc
$39 for a Jetibox

http://www.espritmodel.com/jeti-tele...rogrammer.aspx
If that is too much, you can sometimes find them on eBay or the RCG or RCU classifieds
Yep, thats the one. $39
Apr 19, 2016, 06:02 AM
Registered User
Quote:
Originally Posted by thurmma
Ok, I have aGP-176EVO with a tach port that drives an RCExcel tach just fine. I ordered the mrpm-ac and configured it as thought it was a dle ignition with tach port and no luck. I swapped the connector around and still nothing. I have the red wire from the module connected to the white wire from the tach port and the black to the black.

I saw at one spot where someone mentioned having to program the module to change the number of poles. Does this have to be done? If so, does it have to be done with a Jetibox? If it does, then someone is going to get a screaming deal on this module.

Thanks in advance for the help. I am using a DS-14 and the module is recognized. I have it set to display on the main screen along with logging.

I am using this with a CB200 and 2 3channel rx's on pin 14 set for telemetry input.
Do you have the NEW Gp ignition or the older RcExl version ? I have personally used the MRPM-AC connected to the tach port of a GP-61 (older RcExl ignition) and it worked perfectly. I did however need to connect the MRPM-AC reversed from what you describe. I connected the Black MRPM-AC input to the White tach signal wire and the Red MRPM-AC input to the Black tach negative wire.

You must change the number of poles to get a correct reading and as I recall it needs to be set to Two poles and this can only be done with a Jetibox or equivalent but you should be able to do it with the Jetibox app on the transmitter if you have access to that on a DS14. As for apparently being unwilling to purchase a real Jetibox, that's up to you but for $39 I've found it a very useful too to have.

Wayne
Apr 19, 2016, 07:22 AM
Registered User
Quote:
Originally Posted by ltc
$39 for a Jetibox

http://www.espritmodel.com/jeti-tele...rogrammer.aspx
If that is too much, you can sometimes find them on eBay or the RCG or RCU classifieds
Thank you. I was wondering if that one would work :-) I wish there was a way to like a post like there is on GSN.
Apr 19, 2016, 07:25 AM
Registered User
wfield0455, I have the new ignition. I was trying to figure out the jetibox app last night but, ran out of time. I will give it a shot again tonight :-)
Apr 19, 2016, 07:51 AM
Registered User
Quote:
Originally Posted by webbsolution
If we dumb Johns data down the details lean towards -

Auto Frame output spacing appears to be "questionable" if you are also using a third party FC one should not use that feature.

Failsafe will be unlikely to actually deploy unless you turn off your TX in flight...

Q% reports are questionably inaccurate - it could be a sync issue but the general lapse in functional feedback appears to really bring into question the functional value of such a pivotal Data point.

John - you have a sharp mind and an objective approach to technology that is refreshing and at the same time objective.

Thank you for your efforts.
Quote:
Originally Posted by Geoff_S
Cravenjw - very nice work !

I had been thinking about buying some OpenLog devices and using them to simultaneously log the EX bus data at the rx and tx while doing range tests, but have too much else going on Looks like you might have done something similar.

Just a comment about the EX Bus jitter. The Jeti spec states that if the rx loses signal, it will not output any EX Bus data. I'm guessing that the large jitter you're seeing is actually this effect, and not really jitter ? I'll admit I have only quickly skimmed over your results....

Likewise, what failsafe setting did you have on the rx - was it meant to drive servo 1 to a fixed value ? The large variations in PWM intervals (which are suspiciously grouped around multiples of 10 ms, ie the period between outputs when set to 100 Hz) make sense if that servo failsafe was set to "Output OFF".

Perhaps I should just wait for your separate thread before asking more questions
The new thread has been created here for those who want to follow and or participate in the discussion.
Data Driven Discussion of Jeti A1/A2/Q, Range, Signal Loss, PWM and Failsafes
Apr 19, 2016, 08:34 AM
Thread OP
Quote:
Originally Posted by cravenjw
The new thread has been created here for those who want to follow and or participate in the discussion.
Data Driven Discussion of Jeti A1/A2/Q, Range, Signal Loss, PWM and Failsafes
Thank you, this is much better. Separate thread really helps keep relevant information together, also it helps with our communication with Jeti engineers.

Zb/Esprit
Apr 19, 2016, 01:23 PM
Tadders
Quote:
Originally Posted by en_spt
Probably no as there are a few problems with that scheme for GPS Triangle:
1. If you wait until you have passed the turn point plus the latency in the system and your reaction time, and then start turning you will be a long way past the right turn point
2. There will be many times (due to thermalling etc.) where you won't be that close to the turn point. The allowable turn zone is actually an infinite triangle on the outside of the turn (i.e. there is no exact Lat or Long to set up for an alarm)
3. Systems such as Skynavigator are fully integrated with the Jeti system (via the RCDroidBox) and give you turn radius advice and advanced warning of the upcoming turn, as well as showing the allowable turn sectors on the outside of the triangle.

https://play.google.com/store/apps/d...gator&hl=en_GB

Simon
I wasn't going to use an exact Lat long but a combination of less than and greater than comparisons.

I have tried but lat and long don't appear in the sensor fields for an alarm. Am I doing something wrong?

Phill
Apr 19, 2016, 02:14 PM
Also known as simon_t
en_spt's Avatar
Quote:
Originally Posted by Toad62
I wasn't going to use an exact Lat long but a combination of less than and greater than comparisons.

I have tried but lat and long don't appear in the sensor fields for an alarm. Am I doing something wrong?

Phill
I think you still misunderstand how GPS triangle turnpoints work - you need to study that before trying to work out how indicate a turn point. Effectively the nominal triangle that you programme in becomes 'dynamic' once you are flying, depending on where you actually are in relation to the next turn point. In the real world you might follow a thermal for a bit, which might take you inside or outside the triangle. Once you resume the triangle you don't need to fly back to the nominal triangle turn point, but a 'virtual' point that will be within the turn point area (this is calculated and represented on the screen in a GPS triangle App like Skynavigator)

Even if you could find the sensor fields I still don't see how you could get this to work as the borders of the areas outside of the turns representing 'allowed to turn' can never align with a single Lat or Long value associated with all three turn points - at best if you were very lucky with your triangle alignment, you might get one border (of the two per turnpoint) to align out of the three turnpoints.

Simon
Apr 19, 2016, 03:50 PM
Tadders
Quote:
Originally Posted by en_spt
I think you still misunderstand how GPS triangle turnpoints work - you need to study that before trying to work out how indicate a turn point. Effectively the nominal triangle that you programme in becomes 'dynamic' once you are flying, depending on where you actually are in relation to the next turn point. In the real world you might follow a thermal for a bit, which might take you inside or outside the triangle. Once you resume the triangle you don't need to fly back to the nominal triangle turn point, but a 'virtual' point that will be within the turn point area (this is calculated and represented on the screen in a GPS triangle App like Skynavigator)

Even if you could find the sensor fields I still don't see how you could get this to work as the borders of the areas outside of the turns representing 'allowed to turn' can never align with a single Lat or Long value associated with all three turn points - at best if you were very lucky with your triangle alignment, you might get one border (of the two per turnpoint) to align out of the three turnpoints.

Simon
Ah, I get it now! I didn't realise the turn point was a sector.

It would still be nice to be able to set an alarm based on position to indicate say a flying field boundary.

Phill
Apr 19, 2016, 04:00 PM
3D? I only got two thumbs!
Perhaps a DC/DS-24, a little geometry, and some lua scripting?
Apr 19, 2016, 04:02 PM
Also known as simon_t
en_spt's Avatar
Quote:
Originally Posted by Toad62
Ah, I get it now! I didn't realise the turn point was a sector.

It would still be nice to be able to set an alarm based on position to indicate say a flying field boundary.

Phill
The Skynavigator android App gives you all the warnings you need - audio, visual and text at the side of the triangle map. If you haven't tried it then it is worth going to a practice session where there are normally systems available to put in your own model to try it out. Most people find the combination of flying and data overload takes a bit of getting used to. You might find once you have had a go that you will have clear ideas on what the radio can do to help you, if it isn't already done by the existing telemetry and triangle apps.

Simon
Apr 19, 2016, 04:21 PM
Tadders
Quote:
Originally Posted by en_spt
The Skynavigator android App gives you all the warnings you need - audio, visual and text at the side of the triangle map. If you haven't tried it then it is worth going to a practice session where there are normally systems available to put in your own model to try it out. Most people find the combination of flying and data overload takes a bit of getting used to. You might find once you have had a go that you will have clear ideas on what the radio can do to help you, if it isn't already done by the existing telemetry and triangle apps.

Simon
Thanks Simon,

As I am an Apple user I was hoping to avoid buying an Android device to run SkyNavigator. Apparently the IOS version only supports Weatronic.

I've got the MGPS and Rcdroidbox and am awaiting an Android tablet so should be able to see it in action on Saturday at Baldock.

It's going to be an exciting day as I'm hoping AEB will fly the maiden of my Paritech ASW20.

Phill
Apr 19, 2016, 05:08 PM
Tadders
Quote:
Originally Posted by AeroKen
Perhaps a DC/DS-24, a little geometry, and some lua scripting?
Wow, I didn't realise scripting was a possibility for DC/DS-24.

You have just given me all the justification I need for getting one!

Phill


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