thUndeadMod v3.4 - openLRS S**T just got real :)

[WSWhitby]

OK Its still snowing so I will be unable to conclude / progress my trials and tribulations with a range check.
On the bench at very short range I have got the "System" working.
The system is Eagle tree e Logger, GPS, Altimeter, Pitot airspeed add on and stabiliser. Rx, I have used both Flytron and Orange from Hobby King, They still owe me one HK that is. Transmitter is Flytron M2 module Fitted to a Futaba T9CP, I await the Orange HK Transmitter module along with a Turnigy 9X transmitter and a Flytron JR to Futaba transmitter module adapter.
The FW in both RX's is configured for mixed PPM serial and parallel, output Serial on out 4. 10KHz channel spacing and 6 channel randomly selected channels  (for Hopping). 
I have tried both V4 and V3.6 and with some code modification both seem to perform equally well.
The RSSI is difficult to check at short range but by modifying the boost function I was able to reduce the power to 1 dBm, by using the Transmitter button, This gave some indication that it was working but not very conclusive. More of that when I finally get the weather conditions to enable me to do a range test.
When I get the opportunity I intend to do the range test above Castleton up towards Breaky Hill and Castleton Rigg an area that I know and also the site of previous trial by Coyte it may give us some form of comparison. I hope by then I have the Turnigy and will be able to draw this trialing to a close and get some flying in.

Regards

John

[WSWhitby]

Thanks for that, I almost bow to your experience but in my defense I did read the Eagle tree data sheet for the OSD, unfortunately can not find it right now so I am quoting from memory but it says that SOME receivers require a high impedance on the RSSI output. Well as the output from the both my receivers comes straight from the AVR mega 328 I consulted the data sheet for the Mega 328. No such restriction was mentioned. As for effecting the range I am totally bemused as to how the output load of one of the processor pins could effect the quite separate rf module. I suppose if operating into a short circuit and not damaging the processor out put, not very likely, it may drop the Vcc of the processor, this could cause "grey out" but to be honest I remain unconvinced that the input impedance of the Eagle tree OSD could cause problems with LSS Open Rx's range. I have however sent a  support email to Eagle tree seeking confirmation and the value of the input impedance. I will also post a question on the Flytron Forum to ascertain the the views of The designers. By the way excuse my ignorance but what does "bounce up" mean when applied to a processor input ?
I can see some logic in buffering and smoothing the output as It is a series of pulses that are generated in software and consist of 10 or 20 samples depending on the Version. I have checked the pulses on a scope and into a capacitor and resistor combination for smoothing. That would simple go Some way to converting the pulse out put to its RMS value. I can see no reason why this smoothing circuit should not be included but always I like not to over complicate circuits without a full understanding of what is happening as I was told as a youngster KISS.  So far no smoke from the Receiver or the OSD so all will have to wait for the range check to try the final part of the tests.

Regards

John   

[WSWhitby]

Hi John (papa)
Done a simple test on the bench to test loading. Connected RSSI out from Rx to Tmp1 in on eLogger. Measured whilst connected to the RSSI output from Rx. Disconnected the RSSI input into the e Logger, whilst continuing to display waveform on scope. Hence I have loaded and unloaded measurements. If loading is effecting the signal I would expect the amplitude or the wave form to change, in fact with severe loading The signal should reduce considerable in amplitude. Not bounce! You can easily try the test yourself as you have a scope, in fact I hope you do so me can get actual data out on to the Forums rather than our opinions. My results are :
When connected waveform is 0.2 mSec pulses, changing slightly in length by about 10 to 15%, 3.2 V amplitude at 2.5 Msec period.
Unconnected as near the same as makes no difference.
Hence buffering for reduction in loading not required in this case
Tests repeated with both Orange and Flytron Rx's same results .
This does not surprise me as the un buffered absolute maximum sink and source current of the Atmel 328 Mega taken from the Atmel data sheets  is 40 mA, given an absolute chip max of 200mA. I doubt that any one in there right mind would design an input that required that kind of drive, unless it was differential current as in RS 433/485 for very high noise environments.
I am not suggesting that the EagleTree  unit is defective, you really must read my posts more carefully, I said I would  request the value of the input impedance, which I have done.
What Rx do you use for your epic flights ? I assume its not Flytron as no one would risk their expensive gear on a"cheap and lazy design" or would they?
Please carry out the simple test as above and let me know how you get on you never know we may both learn something. I can send you a PM with the connection diagram scope settings, test conditions ect if you want to replicate the test.

Regards

John
 

[WSWhitby]

Hi John (papa),
A couple of your posts seem to have disappeared, is this a system malfunction or are you modifying your opinions? It would be nice to know what has prompted you to delete them if this is not a system problem.
The above was not the main purpose of this post it is to correct a mistake I made in my last, promise not to delete it  ;) post.
I said the period of the waveform was 2.5 msec well it is actualy 2.0mSec.  :-[

Regards

John

[papa_lazerous]

I'm not here posting opinions, just facts based on experience. I'm not interested in wasting my time with you any further after your previous post. I urge you to do as you want and find out the hard way.

Sent from my GT-I9300 using Tapatalk 2

[WSWhitby]

Hi John
The hard way is to do tests and publish the result, that I have done. The easy way is to make incorrect statements then delete them when proved wrong. My intention was not to alienate any one but to get to the truth. Your experience will be missed

Regards

John

[papa_lazerous]

Have you flown over 10km and back on this hardware,and I'll add I did it why 5.8ghz video on 200mw. When you have done that we'll have a pissing contest. I don't post to have to defend my posts I've got better things to do I've not been wrong with what I've said, you'll find out in the long run good luck!

Sent from my GT-I9300 using Tapatalk 2

[WSWhitby]

John,
If you had left your posts on the board others could judge the rights and wrongs. Only the unsure or wrong would retrospectively hide their opinions. This is not a P****ing competition its a search for the facts. If you have any other admissions of wrong doing (10Km undocumented flights) please use PM's we do not want the Pastime brought into disrepute by some over large egos.

Goodby I still don't understand your attitude to the truth Remember what Napoleon said " Man who never made mistake never made any thing"

Goodby

John

[Coyote]

Off topic : What rx antenna were you using on that flight John ?

[papa_lazerous]

Diamond on the tx home made dipole on the rx I've got GPS tracks to verify my range but don't advertise it because of the sensitivity over the range and the trouble it can cause. I've got serious trouble with my video as I get corruption with static I have video usable to 8km before the recorder didn't recover the recording. I believe you've seen it Ian? I can make or available for a limited time via drop box

Sent from my GT-I9300 using Tapatalk 2

[Coyote]

Yes I`ve seen that one John, I can confirm it.

Sorry bud, I didn`t explain, I meant video Vrx antenna used

[papa_lazerous]

Clover leaf on the plane (skywalker) mounted on the flat behind the prop on the tail boom. On the ground I have a skew planar wheel as my omni and I have a helical on my pan and tilt tracker 7turns I think. I get crystal clear image over 5km just on the skew though!

You need to be extremely anal over every single detail to get extreme range from 5.8 I've not reached my limit just ran out of bottle and want sure about battery but I know now I could go further easily as I glide for 15-20 minutes over head circling when I get home to lose height to land.

Sent from my GT-I9300 using Tapatalk 2

[Coyote]

Cool, thanks for the info :)

[phibin]

i have been thinking about dipoles on the rx,
and the great ranges they have been achieving..

could you make this...



but have the ground element 'normal' flexable antenna wire for a multi?
as long as it was the correct electrical length?

or would it not really work as its flopping around not at its full length?

simon.

[WSWhitby]

Thanks to thUndead for support and confirmation in PM will act on good advice on facts and carry on with test and publish results when I have something testable to report.
How about re joining  the fold I am sure we have more bits and pieces that need some expert help.

Regards

John