Output RSSI on a channel

[jhsa]

Hi Guys, the following settings allow to send RSSI on a channel. I checked on my radio and it seems to be working. The values of the channel match exactly the RSSI values, from over 100% down to about 36%..
My question is:
Is there a way of doing the same easily, and with the same accuracy I am seeing??

I don't use this myself, but a friend asked me if it was possible and I took the challenge I have nothing to test it apart from my radio

Thanks

João

Go to Model setup/General and turn the "Extended Limits" ON.

Now go to the mixer and configure a channel.

Ch6 80% SC1 (Scaler 1)

Disable trim as you don't need it anyway.

Go to Model Setup/Limits, Ch6, and set "min" and "max" limit to -/+125%. Leave the sub-trim at 0.

The weight at 80% and extended limits at +/- 125% allow for the value of the Channel (in this case Ch6) to go over 100%, actually, 125% max.. Sometimes the RSSI is above 100%

Now go to Model Setup/Globals/Scalers.

SC1
Source RSSI
Give it a name.
offset 1
multiplier 102
divisor 10
unit Pcent
sign +
decimals 0
offset at "First"

These are the values that worked for me. The displayed value on my radio is exactly the same from over 100% down to 36%. I put the radio in range test mode to check it.. You might have to play with the multiplier and the offset, but i think these might work.

To compare both values, go to Model Setup/Globals/GVARS and set the output of Ch6, which is "O6" (not ch6), as source of the GV1, for example.

Go to the Telemetry Custom Screens and select RSSI and GV1 to be shown on one of the screens..
Now you can compare both real RSSI and the value of the channel through GV1.

Connect CH6 to the flight controller and see if it matches

[samys13]

Good news for me, i will try this on evening. Thanks jhsa

Envoyé de mon GT-I8190 en utilisant Tapatalk

[andrewju]

João,

I just checked this config on my XJT + X6R. In principle, it works. Though, the values I get did not match the RSSI by far. I had to experiment with multiplier and offset. Offset = 8 and Multiplier = 115 give me a result that is quite close to RSSI (it's nearly accurate in the area of 50-70 and then it goes 2-3 points higher at RSSI about 80-100).


I tried with the 100% mix:

Ch6 100% SC1

With Offset = 2 and Multiplier = 100 it gives me a pretty precise result in the RSSI range of 44 to 90. If the signal is stronger than 90, there is a minor difference of 1 point (which I believe is insignificant). Though, if RSSI goes above 100 (like 105 or 108), the channel value stays at 100. In my non-FPV'er view this is also not a big issue, as these values can only be achieved with a model close to the radio (I mean, I see no reason to have a really precise RSSI value on the OSD in these conditions).


I guess there may still be a better way to get the "right" values, matching incoming RSSI precisely.

[jhsa]

My values out of the D8R receiver seem to be precise from 36 to over 100. At least comparing the channel percentage from 0 to 125 and the RSSI value coming from the receiver itself. Try to program the GVAR to compare with the RSSI and see if the values are equal or not..
Don't forget to enable "extended limits" in the model setup/General..

João

[andrewju]

That's exactly how I checked mine - by comparing GVAR and RSSI (in fact, that's the only way for me to test it - I don't have an OSD myself).
Extended limits are enabled.

Thinking about it, I believe the "source" of RSSI should make no difference. I mean, it shouldn't matter if RSSI comes from a D8R or from an X-series receiver. But for some reason my results are different from yours. So I may have set something wrong... I need to recheck it again!

[jhsa]

I will post my eeprom later.. At work now.. probably you will only seenit tomorrow


João

[Kilrah]

Note that it probably doesn't make sense "calibrating" things perfectly, given that further calibration will likely be needed for each particular OSD anyway.

[jhsa]

Yea
h, but I don't understand why he is not having the same values as me

[andrewju]

João, you were right! I configured it once again and now the values match.
I'm not sure what I did wrong the previous time. But that was clearly my mistake.

I'll share this guide on the Russian forum, if you don't mind.

Thanks!!!


P.S. Yes, I agree, it will need to be calibrated on the OSD side anyway. But that's another story!

[jhsa]

I'll share this guide on the Russian forum, if you don't mind.

Thanks!!!

Of course I don't mind, that is why I have started this thread.
When you do it, please post a link here so people can find it..

João

[andrewju]

I will, indeed!

Thanks!!!

[Ltomi78]

Hi
I habmve t9x radio and standard er9x fw on it.
I m planning to do the frsky mod on the radio
Right now with the standard er9x fw i cannot find "RSSI" as source option...when i scroll among sources i see sources from RUD to CH16 after that i have 4 blank option.
Maybe i need update to frsky or ersky version of er9x? Or need to us epee to find rssi within the source list?
Please help.

[sportsfan12321]

I tried this approach on my T9X-Pro, and while I confirmed the scalar variable value matches RSSI (using the suggested telemetry custom view mode), the value received on my FC does not match.

Specifically, the RSSI value received on my FC is always higher (e.g. true RSSI is 80, while naze32 says 95). There is correlation between the values though (i.e. lower true RSSI -> lower received RSSI on naze). Is this a trimming-related issue, or something else I am missing?

My setup is T9X-pro w/ FrSky DJT TX, D8R-ii Plus receiver (with 27ms mod), naze32 rev6 running Cleanflight.

Thanks ahead!

[jhsa]

The example I posted above scales the received RSSI from a frsky reciever (only telemetry device I have) and sends it on a channel. It seems to send the right values, compared to the received RSSI:
I don't know what the naze sends as I don't have one..

João

[sportsfan12321]

The example I posted above scales the received RSSI from a frsky reciever (only telemetry device I have) and sends it on a channel. It seems to send the right values, compared to the received RSSI:
I don't know what the naze sends as I don't have one..

João

Right, to clarify that is also exactly what I am doing. The naze is receiving the RSSI value from that channel - it's just that the value received is incorrect compared to what I'm sending out from my 9xr-pro.

i.e., the pipeline is frsky receiver -> 9xr-pro -> put RSSI value into a scalar which is then sent back on a PPM channel (as described in the first post in the thread) -> frsky receiver -> naze/cleanflight receives the RSSI value on that PPM channel (but the value it receives is incorrect - even though I verified via logging a global variable on the telemetry screen that the RSSI value sent on the channel was correct)

[jhsa]

Then the naze might be doing something to it. I wonder if 100% on the naze is something else. Do you know in microseconds what the naze expects from the channel endpoints? ERSKY9X outputs 988 and 2012 at both ends.

João

[sportsfan12321]

I agree.

I believe Cleanflight expects 1000-2000 (per https://github.com/cleanflight/cleanfli ... /Safety.md). And indeed, for my throttle/other sticks, I had noticed the range of 988-2012 received from ERSKY9x in Cleanflight (that was a future question I had - whether trimming was necessary/worthwhile to limit these to the Cleanflight expected range).

I have not had a chance to read into the effects of the multiplier/weight/divider parameters for Scalars, but here's one hypothesis based on my limited understanding:

Is it possible that in ERSKY9x, an RSSI range of 0-100 is (roughly) translated to 1500-2000, whereas cleanflight expects 1000-2000? So RSSI = 80% maps to RSSI = ((0.8*500+1500)-1000)/1000 = 90% in Cleanflight. So perhaps a negative offset is necessary in the Scalar settings? (similar to here https://oscarliang.com/rssi-ppm-channel-taranis/)

[diode121]

I just followed the steps above. I managed to configure the rssi since i can see an rssi value on baseflight.
But the problem is the value does not change. What am I missing?..
Extended Limits are "On".
I'm using Turnigy 9XR Pro with ersky9x-r218, D8r-xp and naze32.
I flashed my naze32 using baseflight and PatrickE's firmware.

[jhsa]

Check your settings again..

João

[diode121]

i doubled check it still the same..
can you please check my wiring..
frsky d8r-xp pin 1 --> CPPM on Naze32..
that's the only connection that i have..
is that right or do i still need to connect something?

[jhsa]

Are you receiving telemetry from the Naze on your radio?
I don't use that flight controller so I don't know how to configure it..

Please download your eeprom from the radio, zip it, and post it here..

João

[diode121]

I can see the rssi value on baseflight,but the value does not change.

I'm fairly new to this hobby and i don't know how to download my eeprom.

Can i just have yours and i'll just compare it to mine. I'm sorry to bother you..

[jhsa]

I don't have this programmed on any of my radios as I don't use it..,

and you didn't answer my question
Do you see RSSI (or any other telemetry) on YOUR RADIO? Forget baseflight for the mnoment..
We need to know if your radio is receiving telemetry..

João

[diode121]

sorry about that..upon checking, nothing..

[jhsa]

Thaty is why it is not working How do you want the radio to send RSSI to the controller, if the radio itself is not receiving it from the receiver
What RF module are you using on your radio?

João

[diode121]

frsky DJT..do i need this http://www.hobbyking.com/hobbyking/stor ... ouse_.html for it to work?

[MikeB]

That will get telemetry from the DJT into the radio, set FrSky COM Port to 2.

Mike.

[diode121]

Thank You guys..I can now see rssi on my radio..

Thanks Mike, it was the cable that I'm missing..

[jhsa]

Great that is working now

João

[diode121]

Hi João,
I have another question.
In using this method. Let's say.
If I connect a GPS Ublox on my naze32 (uart2) will i also be able to receive GAlt (Gps Altitude) telemetry data on my Turnigy 9XR Pro?
Or it is only limited to RSSI telemetry?