RTL_433 Stalling on Startup

[Can Cunia]

Not really sure how best to describe the problem in the title, so have used the term 'stalling'.

I'm using rtl_433 to capture data from a Bresser 6in1 weather station via a USB stick on a Raspberry Pi running Bookworm.

I'm using the latest version of rtl_433, but did notice the same problem with earlier versions of rtl_433 and different Linux versions on my laptop.

The problem is that sometimes (not always) there are no readings when starting rtl_433 and I have to stop & re-start 2 or 3 times before getting readings, once started it all works fine for days or weeks. When starting rtl_433, the hardware is always found and the tuner identified etc

The command I'm currently using is:

"rtl_433 -M utc -F json -f 868.3M -s 250k -R 172 -Y squelch"

I did notice the same behavior when I first started using rtl_433 with a much more basic command to test the USB stick.  I'm happy to put this down to the USB stick not always initialising properly, but thought I'd ask just in case there's something I can do to prevent the issue.

[Christian Z.]

Does the RTL-SDR have a FitiPower FC0012, i.e. not the R820T(2)? There might be gain problems on (cold) startup. See https://github.com/merbanan/rtl_433/pull/2417

Latest version in Debian Bookworm is 22.11 and won't have that fix. You need to get a release binary and place it in /usr/bin or build from source and install.

[Can Cunia]

Yes, it's a Fitipower FC0012 tuner.

I'll look into the fix and report back. 

The thing is that the USB RTL-SDR works fine most of the time, even from startup so the only way to know if the fix works is to wait and see.

Thanks for the quick reply.

[Can Cunia]

I thought I was running the latest version but I am indeed running version 22.11, I had built & installed the latest version but it was on another RPi

Sorry for asking what is perhaps obvious.... Is the fix merged / included in the latest version of rtl_433? 

[Can Cunia]

A quick update:

Following a power outage last night, my Rpi restarted but my 22.11 version of rtl_433 did not so I've built & installed the latest version (23.11). 

Initial results look good as I started to get data from the first run of the new version as opposed to 2 or times before the old version would get data.

Old vs New command line outputs...

Unfortunately, I don't have a copy of the old version but I remember there was a reference to 'Auto Gain'

The new version does not have that

.....................

$ rtl_433 -M utc -F json -f 868.3M -s 250k -R 172 -Y squelch
rtl_433 version 23.11-163-ge25cfc0f branch master at 202409200913 inputs file rtl_tcp RTL-SDR

New defaults active, use "-Y classic -s 250k" if you need the old defaults

Use "-F log" if you want any messages, warnings, and errors in the console.
Found Fitipower FC0012 tuner
Exact sample rate is: 250000.000414 Hz
Allocating 15 zero-copy buffers

......................... 

If I get the same startup problem with the new version, I'll report back.

[Can Cunia]

Just had another power outage, unfortunately the 23.11 release did not help.

I looked at the change log and see that there's a fix included in the latest release, oh well..

• Fixed Fitipower FC0012 gain quirk (#2417)

I think the problem may be related to where the antenna is located, I've moved it to another location in the same room and had similar problems before but only when I first installed the Pi, after that it worked fine after power outages / reboots. I'll look into the gain side of things when I have a bit more time next week.

[Christian Z.]

Debian is stuck on that old version which was current on release of Debian. Policy is to only update minor versions and we don't have a major vs minor release scheme.

It should work to install any old version with apt, then replace the binary with one from our releases (unpack, copy to /usr/bin).

Not sure if the gain problems are fully resolved. For other users the RTL-SDR works after aborting and restarting.

[Can Cunia]

Thanks for the replies. I think one part of the problem may be due to USB power. It seemed to work a lot better when running the RTL-SDR from a powered USB hub rather than one of the 4 USB ports on the RPi. It's been running fine now without any power cuts for a few days so will leave it alone and see what happens longer term.

For info, I removed the Debian packaged release of rtl-433 via apt purge and installed the latest github version via sudo install which made the binary available system wide.