Modification of behavior when in range check

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Which board (stock / gruvin9x / sky9x / Taranis) are you using? Taranis

What is your openTx FW version? 2768

A couple of years ago, I lost a nice model when I took off with the FRSKY 
module on my tx left on Range Check.

In view of this, I think it would be desirable to add a (possibly 
selectable/configurable) feature to the firmware so that while in Range Check 
mode with the internal RF module (or external XJT) , and with a Rx that support 
telemetry, the radio falls back automatically to Full Range mode when the RSSI 
drops below a predetermined level (say 40).  I know that the Taranis emits a 
beep every few seconds, which is supposed to keep the user aware of the state 
of the radio, but on a noisy field, distractions abound. This feature would add 
a layer of safety. 

Alternatively, it could be designed to switch back to full range after say 90 
seconds (as it does on Futaba FASST radios).

Thank you and keep up with this fantastic project.

Original issue reported on code.google.com by ululi1...@gmail.com on 11 Oct 2013 at 7:29

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I'm sorry but i do not agree either on:
a) exit from range check after 90 seconds as I want all the time i need to do 
test
b) exit range check if RSSI goes under 40 as it makes impossible to do 
improvements and checks.

when fling with old radios the preflight check list was:
1) turn on the brain
2) check the frequency board
3) turn on the radio
4) check the model memory
5) turn on the model
6) perform surface/model check
7) enjoy your flight

with 2.4ghz we have avoided point 2)
with receiver match we have avoided point 4)
maybe in the future we will be able to have a self check of point 6) and some 
fancy substitutes for points 3) and 5)

but nobody will ever be able to skip point 1) without paying some consequences.

Original comment by romolo.m...@gmail.com on 12 Oct 2013 at 7:08

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@ululi: Don't take it wrong :)

Personnally I don't like the < 40 idea, but I am rather favorable for the > 90s 
idea

Original comment by bson...@gmail.com on 12 Oct 2013 at 8:38

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Thank you for the prompt reply. 

I understand that #1 (Brain on) is the most important thing. Believe me, 
loosing the 
plane that way taught me a valuable lesson! However, we are people, and people 
make mistakes. So, why not taking that into consideration when designing 
systems that 
interact with people? After all, 
if the brain is turned on, then we do not need receiver match. In fact #6 on 
the checklist should take care of that. 
Also, consider that often people ask more experienced modeler to help with 
maiden. In my case, our test pilot assumed that the FrSky module would behave 
as a Futaba, reverting to full after 90 s. I believe JR does the same, but I am 
not sure on that. So I assumed that he had switched back the module to full 
range and did not bother to ask as I was going over the preflight checklist, 
and he assumed that the module would switch back by itself, so did not bother 
to check with me. The red led indicating range check mode was on the back of 
the radio and so out sight, out of mind.

What happened cast a very dark shadow on FrSky hardware in my club, even though 
techically it performed as it was supposed to. In fact, most fellow members 
still cannot unsderstand why I did not switch to Futaba or JR after that.

As for myself, I do not think I will ever repeat that mistake, but it is within 
the realm of possibility...

I understand that it could be a nuisance having to bring the module back to 
range check after a reset. To solve that, 
the RSSI threshold for reverting to full range could be set as a configurable 
variable (or the time lapse), maybe set by default at 0 if RSSI based or 9,999 
s if by time. That way, for all practical purposes it would behave out of the 
box as always, but it would provide an extra layer of safety if set differently 
by the user.   

Anyway, OPenTx is a great firmware no matter what you do with this minor point! 

Thank you again.

Original comment by ululi1...@gmail.com on 12 Oct 2013 at 7:02

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I agree it might be easier to make the mistake with an FrSky module which has 
the LED in the back and makes a rather silent beep.

But with the Taranis the popup takes the entire screen, the sound is much more 
"annoying" and loud...

Original comment by bernet.a...@gmail.com on 12 Oct 2013 at 7:07

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Agreed. However, to me it seems that the imperative #1 for a radio is to 
maintain the integrity of the data stream. So if RSSI drops to a dangerous 
level, and power output can be increased, the radio should do that, unless 
overridden by human input... 
I understand that that may be bad for the user's ego, but I'd rather nurse a 
wounded ego than a wounded plane (or bystander!)...

Original comment by ululi1...@gmail.com on 12 Oct 2013 at 7:18

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The aim of a range check is to have low RSSI to improve/check positioning of 
antenna.
If the radio increase the signal automatically then it's absolutely impossible 
to perform any check/adjustment.
Automatically escape RRSI check mode based for example on stick usage is not 
comfortable if you are performing checks.
Even a timeout is also rather useless, as in 90 seconds you may destroy your 
plane several times...
Maybe the only feasible solution is to disable range check if altimeter is 
installed and altitude is more than 5m.

Anyway the user is normally not expected to fly with main menu active as it 
make impossible to look at telemetry

Original comment by romolo.m...@gmail.com on 12 Oct 2013 at 7:48

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I'd would say that if the threshold setting is set say at 30 or 25 (but again, 
the user may elect to set it at 0), it is possible to do all sort of tests, 
just leave the radio at a distance for which the RSSi hovers say at 40. 

As an alternative, why not have the module go back to full range if the 
throttle stick or throttle channel is moved from the lowest position (or any 
position set by the user)? With RSSI, there is no need to move sticks to do 
range check.

As for the 90 s, I think this reflects how a typical range check at the field 
is done. Set range check, start walking away with radio until signal is lost, 
hopefully 60 meters  or more, walk back, move to the runway, take off. At a 
typical walking speed of 1.4 m/s, walking 60 m will take at least 40 s. Another 
40 to walk back and so 90 s is just about what you need...  

Original comment by ululi1...@gmail.com on 13 Oct 2013 at 1:20

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When you are using the range check feature, you will hear continuos "beeps", 
until you disable the range check. 

Original comment by dehigama on 14 Oct 2013 at 4:15

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My Spektrum TX requires that the trainer switch is held on for the range test 
mode to be active. That seems like a reasonable requirement. This requirement 
could be enabled if desired by a global menu option. When enabled, a popup menu 
could be displayed to prompt the user that the Trainer switch needs to be held 
on.

Original comment by nisch...@gmail.com on 22 Dec 2013 at 7:20