RSSI drops to 12 - but only with a particular model selected

Post Reply
mpjf01
Posts: 367
Joined: Thu Jul 26, 2012 3:07 am
Country: -
Location: Adelaide, Australia

RSSI drops to 12 - but only with a particular model selected

Post by mpjf01 » Fri Feb 09, 2018 1:22 am

I'm not sure where to post this, or even if the problem is OpenTx related. But I'll ask anyway in the hope that someone can give me some clues. I went to use a model today and as soon as I switched on the Rx I started to get low RSSI warnings. I have flown this model many times and have not changed anything since the last flight. I suspected that maybe my Tx had failed somehow so I then tried it with another model and everything worked normally.

My suspicion then moved to it being a faulty receiver. I got another receiver of the same type (S8R) and bound that to the Tx using the original model definition and that also behaved the same as the first receiver - that is low or no RSSI.

The TX works normally unless I select only one particular model in it. I'm not sure now whether the issue is hardware related or something that is happening in the RF module firmware or OpenTx. Before I start messing about changing any of those firmwares is there something I should do to help identify the cause?

In case it's useful I have attached the backup file. The model in question is named MS PHENX S8R.

Taranis X9D+. OTX 2.2.1. XJT RF module firmware 170217. Rx firmware 170816 (not latest).
Attachments
Taranis plus backup 9 feb 18.otx
(32 KiB) Downloaded 74 times

User avatar
Kilrah
Posts: 9495
Joined: Sat Feb 18, 2012 6:56 pm
Country: Switzerland

Re: RSSI drops to 12 - but only with a particular model selected

Post by Kilrah » Fri Feb 09, 2018 7:57 am

Is that only when being close or does it stop when you move away (usual swamping issue?)

If not updating receiver firmware is all that I could think of. If the radio shows 12 it means the receiver sent 12...

Carbo
Posts: 324
Joined: Fri Aug 02, 2013 6:55 pm
Country: Germany
Location: Freinsheim RP

Re: RSSI drops to 12 - but only with a particular model selected

Post by Carbo » Fri Feb 09, 2018 8:11 am

Strange ....
What do you think about
- delete and rediscover sensors
- make a new bind
before updating firmware? Done in a few seconds, only to be sure.

mpjf01
Posts: 367
Joined: Thu Jul 26, 2012 3:07 am
Country: -
Location: Adelaide, Australia

Re: RSSI drops to 12 - but only with a particular model selected

Post by mpjf01 » Fri Feb 09, 2018 10:30 am

No it's not swamping, I'm experienced with that. I rebound the original receiver several times and then bound the second receiver. Also sensor deletion and rediscovery was done this morning with both receivers but it made no difference.

Perhaps I didn't make it clear but both the S8R receivers work normally when I bind them to another model on the same Tx. In fact any other model I suspect (or at least all of the 5 that I've tried). There's something about this particular model/receiver combo that is causing, or at least manifesting, the problem. As I said earlier the model does work normally with a different type of receiver (X8R) suggesting that the issue has something to do with the Rx rather than the Tx.

I won't be able to trust the system until I discover what it is as it might be a time bomb.

I have been using this transmitter fairly intensely this week with a R9M module and a suite of telemetry sensors installed testing different firmwares and transmit power. That's the only different thing that's happened as far as I can recall.

If there's nothing about the existing installation that would help resolve it I'll start by re-flashing the receivers. Then if need be the RF module.

User avatar
Kilrah
Posts: 9495
Joined: Sat Feb 18, 2012 6:56 pm
Country: Switzerland

Re: RSSI drops to 12 - but only with a particular model selected

Post by Kilrah » Fri Feb 09, 2018 10:57 am

Try changing the Receiver number on that model to that of another that works, and vice versa. S receivers have exhibited issues related to some IDs before, which again were solved by a receiver firmware update.


User avatar
MikeB
9x Developer
Posts: 15566
Joined: Tue Dec 27, 2011 1:24 pm
Country: -
Location: Poole, Dorset, UK

Re: RSSI drops to 12 - but only with a particular model selected

Post by MikeB » Fri Feb 09, 2018 11:07 am

There is a known problem when using "early" XJT modules (internal or external) with SxR receivers where they only work with some Rx Numbers.

Mike
ersky9x/er9x developer
The difficult we do immediately,
The impossible takes a little longer!

Carbo
Posts: 324
Joined: Fri Aug 02, 2013 6:55 pm
Country: Germany
Location: Freinsheim RP

Re: RSSI drops to 12 - but only with a particular model selected

Post by Carbo » Fri Feb 09, 2018 11:24 am

Interesting. I want to share my observations from last autumn, when i was testing R9M also. After flashing a new firmware to the external R9M, my internal XJT in my 2013 X9D was dead. No chance to flash it from OpenTX. No chance to flash it over SPort. Power supply was always there, measured directly on XJT. I ended up buying a new X9D plus.

Weeks later i tried again and it was possible to flash internal XJT. I do not know, what happened. I am using my old X9D for testing purposes again, it works flawlessly. I am a happy flasher since 2013 ;) and i am very sure, my method is reliable.

That may be coincidence and without context, just wanted to share.

mpjf01
Posts: 367
Joined: Thu Jul 26, 2012 3:07 am
Country: -
Location: Adelaide, Australia

Re: RSSI drops to 12 - but only with a particular model selected

Post by mpjf01 » Fri Feb 09, 2018 2:15 pm

Changing the receiver number appears to have fixed the problem. I did see this issue myself with early S6R firmware and my X9D transmitter, but never with either of my X9D+ before.

The receiver number that doesn't work is 05. I'll try a few more tomorrow.

It seems peculiar to me that an installation that has been working fine for months suddenly fails when I've changed nothing, the receiver number has never been changed by me.

Thanks for the assistance.

mpjf01
Posts: 367
Joined: Thu Jul 26, 2012 3:07 am
Country: -
Location: Adelaide, Australia

Re: RSSI drops to 12 - but only with a particular model selected

Post by mpjf01 » Sat Feb 10, 2018 5:13 am

I have updated the receiver firmware to the most recent (20171213) non-EU version. This made no difference to the original issue, the same Rx numbers worked as before and the same didn't work. I tried the same with my earliest model X9D and some receiver numbers were OK, some not. I had thought that this matter was resolved last year but clearly not.

I also tried binding the Rx to my X12 running FRSKYOS. Some of the receiver numbers that didn't work with my X9D+ (all that I tried) do work with the X12. I haven't tried all possible numbers of course.

Daedalus66
Posts: 1769
Joined: Tue Dec 27, 2011 8:22 pm
Country: -
Location: Ottawa

Receiver number issue binding S6R

Post by Daedalus66 » Sat Apr 14, 2018 8:16 pm

I have a very early Taranis A01, one of the first batch sold by Aloft, and ran into the mysterious receiver number issue. It wasn’t until I found a 2016 post by MikeB that I realized why I couldn’t get either an S6R or an S8R to bind with it, even though they bind fine with my QX7. I tried receiver numbers 3 and 4, but it wasn’t till I went to 1 that it worked.

According to Mike, in the very early Taranis:
“0, 3, 4, 7, 9, and 10 didn't work but 1, 2, 5, 6, 7 and 8 did work.”

Both receivers have the latest international firmware. The transmitter still has the original early 2013 firmware.

I’m assuming there’s no fix for this issue and that one just has to work around it.

Post Reply

Return to “openTx for FrSky radios”