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Dec 23, 2015, 02:01 PM
nigelsheffield's Avatar
I can test too of course, though only bench testing as weather is awful.....
If it works out it is a simple solution to an age old problem that frsky should of thought of years ago......
When I tested the 801 code on the 802 I did not get any swamping problems so as long as the switching on or off during flight does not do anything odd then it should work...
Latest blog entry: Eachine twig 115
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Dec 23, 2015, 02:15 PM
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midelic's Avatar
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So on original frsky rx it is the same problem.
Dec 23, 2015, 02:43 PM
nigelsheffield's Avatar
Yes, d8r d4r don't generally do it but all x series ( d16 ) have swamping poroblem.
I asked WAY back if the sensitivity could be reduced when signal was too high causing swamping but got the usual frsky reply " we will consider it " ... And then nothing...

It's potentially quite a dangerous situation, if someone does not set failsafe properly a motor could start on bench, also consider a quad where it has return to home programmed as failsafe, I've seen them just take off on their own with the user looking shocked and watches as the quad flys up then lands a couple of feet from where it took off lol....
Latest blog entry: Eachine twig 115
Dec 23, 2015, 02:57 PM
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midelic's Avatar
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@Nigel
I would need a RSSI log to see when swamping happens what is the RSSI.I can think of something in Base of that,For example we know the RX the farthest it goes the RSSI is going down.I saw your Taranis log with RSSI and altitude and see the RSSI is quite good(high) for long range..so the margin doesn't seem to large to play with .And on top of that I want to see when swamping happens ,....the RSSI is up or down...If it is going down there is not much what I can do.
Dec 23, 2015, 03:01 PM
nigelsheffield's Avatar
Midelic ,
You probably already considered this but turning off pa/LNA at a certain level is OK , then it needs a lower level to turn back on again , this may be the tricky part, getting the levels so that it does not keep osculating between the 2,
As a start I notice the swamping when rssi levels hits around 115 120, setting the upper limit to 100 would be ok, maybe even lower as 100db with pa /lna is probably close enough to work without the pa/LNA.
Maybe turn back on if rssi with no pa/LNA goes under 50?
Latest blog entry: Eachine twig 115
Dec 23, 2015, 03:04 PM
nigelsheffield's Avatar
If swamping if already occurred then rssi goes down so at that point nothing can be done ...
So trick it is to turn off pa/LNA early before swamping starts ...
Latest blog entry: Eachine twig 115
Dec 23, 2015, 03:49 PM
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midelic's Avatar
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You catched it quickly .When I said the range is narrow I was reffering to a value if LNA enabled not jumping again over 100.I was thinking the same as 100 but not sure what should be the lower value.
I will make a test version with 100 and 50.
I hope you are right the swamping occurred on high RSSI ......if on lower there is nothing I can do.
Last edited by midelic; Dec 23, 2015 at 04:24 PM.
Dec 23, 2015, 03:59 PM
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midelic's Avatar
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Ok test this one .See if something improved.
I disabled only LNA.
File Removed.it was just for test.
Last edited by midelic; Dec 24, 2015 at 05:38 AM.
Dec 24, 2015, 05:12 AM
nigelsheffield's Avatar
sorry did not realize you had posted this last night...
I just tested it now and looks wrong, close up there is no swamping and rssi level is around 80, however as i move away the rssi start going up an down like lna being switched on and off, but worse still is the range test shows much reduced range, like lna is switched off instead of on when signal gets low. once rssi drops to zero it does not come back again till i move much closer to rx so looks like lna IS switched off when signal is lower....

maybe something to do with inverting the rssi levels compared to frsky, remember the rssi levels were oposite to frsky at first ?
Latest blog entry: Eachine twig 115
Dec 24, 2015, 05:20 AM
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midelic's Avatar
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No it is not that...The RSSI raw values are not fixed ....it fluctuates quite largely in short period of time.In your log the samples are taken in wider time frame than actually is.In order to get something it needs some averaging of many RSSI raw values and compare the averaging result with a preset value.
I will try to do something...
Last edited by midelic; Dec 24, 2015 at 05:26 AM.
Dec 25, 2015, 01:59 PM
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Dec 26, 2015, 01:27 PM
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Hi,
on low range between antennas (tx and rx) i lost signal and telemetry from my RX-F801 - it is normal?
RX-F801 (0 min 25 sec)
Dec 26, 2015, 01:41 PM
Registered User
This has been discussed several times already, in fact on this very page. Signal swamping, it's normal.
Dec 26, 2015, 01:52 PM
Registered User
Thanks, I just read only few pages and successfully upgrade firmware with telemetry TX.
Dec 26, 2015, 05:32 PM
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VicDzen's Avatar
Today I received a pair of those guys: http://www.ebay.com/itm/130682846209
And have to say, that they are built on Atmega8L and onboard switch 3.3/5 actually switches power supply for Atmega, so, you can't exceed the voltage of programming signals if you choose 3.3V for our TXs

But it may be necessary for somebody to bypass TX 3.3 LDO in order to make programming process more reliable.


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