status of itron SCM (power meters)?

[Greg Troxel]

Every time I look again rtl_433 does more!

Someone pointed me to rtlamr, and I was was able to receive a few
meters, SCM messages. However they are type 12 and not sure what that
means.

I am trying to run rtl_433 on the same dongle/computer like so

./rtl_433 -f 912600155 -s 2359296 -M level -M protocol -M bits -C si -M newmodel

to match the values used by rtlamr, but am not seeing anything. I
suspect the signals are weak as the closest smart meter is about 80m from
the rtlsdr dongle.

So I wonder:

any hints about what I should be doing different?

is there any notion of a decoder having user-facing docs of preferred
freq and samplerate? I had known these were "915" but it seem they
are 1) 912.6 and 2) pretty wide, probably due to FH SS.

is anyone else receiving SCM messages?

does anyone have wisdom/experience on relative ability to receive weak
signals from rtlamr vs rtl_433?

Thanks,
Greg

[Christian Z.]

If you want to read weak signals use

    -Y autolevel -Y minlevel=-30 -Y magest

to report some stats on the levels add

    -M level -M noise

The -M newmodel is deprecated now.

There are some ideas to add help and info to decoders. Unclear if we should really add that as code or pre-process the doc-comments somehow (not sure if a build-dep to e.g. Python is acceptable).

The infos from the doc-comments are available in the decoder explorer: https://triq.org/explorer/ -- might perhaps be enough to just offer a prominent link for each decoder?

(quick search "scm" then click the "green lines" icon)

[allenm]

I have accessed my Itron electric meter several ways. At present I’m using rtlamr to write to a csv file which I read with a Python program I wrote which then writes to an Influx database which Grafana accesses to generate a graph.

Here’s the rtlamr command I use: rtlamr -centerfreq=915000000 -symbollength=32 -tunergain=40 -msgtype=scm+ -filterid=69355852 -format=csv > meter.csv

But in the past I also just used rtl_433 to output to a mqtt file. Then I used a Python program I wrote to read the mqtt file. For that I used this command: rtl_433 -f 915M -g 40 -s 1M -R 160 -F mqtt

Some of the parameters may seem similar between rtl_433 and rtlamr, but you have to use their own set of parameters.

As far as weak signals, at first I had the opposite problem. I was using my roof mounted 2m/70cm antenna and was picking up over 50 meters around the neighborhood. That results in a lot of unnecessary processing time and signal conflicts.

I now use one of those little RTL-SDR indoor antennas and only pickup 2 other meters besides my own. As a result my meter gets thru more often,. It varies between once a minute to maybe 20 minutes. That’s mainly because they use a random delay between unsolicited transmissions. The meter reader truck apparently polls meters and gets a transmission right away.

You may know this, but the meter transmits 2 more digits of accuracy than the reading shown on the meter. I calculate the difference between the previous and current readings to get watts used in my Python program.