Using rtl_433 with Airspy R2

[Simon Hammond]

Hi, is anyone successfully using rtl_433 with an Airspy R2?

I’ve enjoyed using it on a headless Raspberry Pi with an RTL-SDR V3 using a discone antenna with LaNA LNA. Obviously with the V3 I was able to set the bias tee to always on to power the LNA, something I don’t believe I can do with the Airspy.

SoapySDR detects the R2, as does airspy_info, and the following string gets it running: -

rtl_433 -d driver=airspy

However, I see no output. Is this because the LaNA isn’t powered? Can anyone help me get this going?

Many thanks,

Simon

[Christian Z.]

You likely need to set gain, see "-g" help output.

For the LNA, if you known the option to set you apply that with "-t"

[WessexWeather]

Thanks for your reply Christian. I didn't think Airspy supported the -t option, however I've tried: -

rtl_433 -d driver=airspy -t biastee=true -g 20 (and -g "" for auto)

and still I get no output.

[Christian Z.]

Verify what data rtl_433 is seeing, https://triq.org/rtl_433/ANALYZE.html

Or try the rtl_tcp passthrough to watch rtl_433 live. https://github.com/merbanan/rtl_433/pull/1915

Works also with other SDR apps and https://github.com/pothosware/SoapyRTLTCP now.

[WessexWeather]

Sorry, I’m a relative newbie and still none the wiser. I have success with my RTL-SDR dongle but not with my Airspy R2. SoapySDR is set up correctly and finding the devices.

I can’t use rtl_tcp with the Airspy can I? 

All I want is to be able to use rtl_433 with the Airspy R2 with bias tee on to power my LNA. Surely this is possible somehow?

[Christian Z.]

As far as I know nobody ever reported trying an Airspy (R2). Would be great to document what's needed.

The usual points to check would be gain (there should be LNA,  MIX, VGA, e.g. the HackRF has LNA=#,VGA=#,AMP=# and LimeSDR needs -g LNA=20,TIA=8,PGA=2),

and that the actual signal level is correct, best to use "-Y autolevel".

If you can check out https://github.com/merbanan/rtl_433/pull/1915 and connect to the running rtl_433 to inspect what it's "seeing".

[WessexWeather]

Sorry Christian, this is above my pay grade!. I tried appending -Y autolevel and whilst the noise was continuously monitored and adjusted, I didn't record any signals. As far as all those gain settings are concerned, I don't know where to start.

And the link you've shared, I'm not sure what to do with that either I'm afraid. The instructions are limited.

I too think it would be great to document what's needed, as I'm sure there must be other Airspy R2 users wanting to try rtl_433, but I need a little more help, or someone with experience to chime in.

[Christian Z.]

Did you install rtl_433 from a package manager or compile and install yourself? If the later, the feature mentioned will be generally available in a week or so. Otherwise with the next release (a month or so).

Then you can inspect the live waterfall arriving at rtl_433 and check if it looks reasonable (gains, band, ...).

[WessexWeather]

I compiled and installed it myself. Will wait and see what next week's update brings...

Perhaps I should have just stuck with my £30 V3 rather than the £200 R2!

[Andrea Lawendel]

Unlike Simon, I have installed RTL_433 with Homebrew, but a "rtl_433 -d driver=airspy" option only results in a "No input driver for SoapySDR compiled in". 

A list of other Brew forumlae installed includes soapySDR, but a soapySDRutil query answers no devices are installed. 

What would you suggest? Could I try having Homebrew to install the full Pothos suite from their proprietary tap, or would you recommend re-compiling RTL_433 right away? I'm using a Macbook Air M1 with Monterey, is it feasible?

Many thanks!

Andy 

[Michael Cadiere]

Curious if this would work
-d "" -g LNA=10,MIX=10,VGA=8

[Christian Z.]

Unlike Simon, I have installed RTL_433 with Homebrew, but a "rtl_433 -d driver=airspy" option only results in a "No input driver for SoapySDR compiled in". 

The brew formula isn't great, the input options are not defined.

( -DENABLE_RTLSDR=? -DENABLE_SOAPYSDR=? -DENABLE_OPENSSL=? )

https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/rtl_433.rb 

So if you install SoapySDR first (with header files) and then rtl_433 you will get SoapySDR input. Otherwise you don't.

[Christian Z.]

>  is there a way to build it on macOS without Homebrew?

Sure, if HomeBrew has all the parts needed to compile and install then you should be fine to just compile yourself (compiler, git, cmake, and some libs needed).

See https://triq.org/rtl_433/BUILDING.html#cmake

Be sure to uninstall rtl_433 from HomeBrew first.

Watch the CMake messages like:

-- IPv6 support enabled.
-- Threads support will be compiled.
-- OpenSSL TLS support will be compiled. Found version 3.0.5
-- RTL-SDR device input will be compiled. Found version v0.6-20220115
-- libusb-1.0 error messages are available. Found version 1.0.26
-- SoapySDR device input will be compiled. Found version 0.8.1-unknown

[Greg Troxel]

I have been building rtl_433 on macOS after building the rtl-sdr library
with pkgsrc. Indeed "cmake .." is uneventful.

IMHO it isn't really a good idea to use rtl_433 packages because any
package will be a formal release which is most of a year old. Unless
packaging systems have snapshots, which I think is a bug...

[Andrea Lawendel]

Following Christian instructions I managed to built a RTL_433 executable which now resides in /usr/local/bin. During make install process however I encountered the following warnings:

-- Installing: /usr/local/bin/rtl_433

2022-09-08 17:13:54.198 xcodebuild[78811:3123477] Requested but did not find extension point with identifier Xcode.IDEKit.ExtensionSentinelHostApplications for extension Xcode.DebuggerFoundation.AppExtensionHosts.watchOS of plug-in com.apple.dt.IDEWatchSupportCore

2022-09-08 17:13:54.198 xcodebuild[78811:3123477] Requested but did not find extension point with identifier Xcode.IDEKit.ExtensionPointIdentifierToBundleIdentifier for extension Xcode.DebuggerFoundation.AppExtensionToBundleIdentifierMap.watchOS of plug-in com.apple.dt.IDEWatchSupportCore

RTL_433 launches normally and the -d "" command option let me to correctly identify a Airspy R2 (which was my original goal). So far, reception with the old rtl dongle setup was fine.

Andy