Meter Reader using rtl-sdr

Friend mentioned that he received a device from the local electric utility that lets him monitor his home energy use in near real time.  After I ordered the same (free) device, I thought about using my rtl-sdr to do the same thing.

There are programs existing for the purpose and I figured it would be trivial to use them.

What I found:
First, it's not trivial.  I should have known that.

I wish I had followed this order:
1. Calibrate the rtl-sdr.  I roughly followed the steps on this website: http://rtl-sdr.sceners.org/?tag=calibrate-rtl2832u
The calibration is sensitive to temperature.  So, run a program like sdr# for a while to get the device warmed up.

Get the kalibrate program.

run it:
kal -g 42 -e 22 -s 850

The output:


Seed it with a ppm (e.g., 41) and pic the strongest channel from above step (250 in my case)
kal -e 41 -c 250 -v


...and finally


Now you have the 36 ppm as the offset you need.