12/05/2013

RTL28232U with the ELONICS E4000 Tuner

Yeah, they are pretty much hard to get these guys as i heard the Elonics company folded out. But still, i was able to obtain a couple of these from the US at a cost cheaper than the R820T version !
Initial tests reveal that these tuners are pretty much sensitive than the R820T and Fitipower based tuners. Plus it has a wider 'tunable' frequency range than the R820T.










11/21/2013

Displaying EFERGY E2 Transmission data on MRTG

Using a Raspberry Pi with a RTL-SDR dongle which is tuned to 433.55Mhz, the captured data from the Efergy transmitter is now being processed using MRTG for a web based 24 hour plot of the house's electrical consumption. lighttpd and MRTG was installed for this purpose.
 

11/16/2013

EFERGY E2 CLASSIC 10 Second Sampling Electrical Consumption Analysis

Here is an Excel Plot of the CSV data captured from the Efergy transmitter using the Raspberry Pi and a RTL-SDR dongle. It shows 10 second sampling capture data between 2AM and 8:20AM of Nov 16,2013.  You can actually see the refrigerator turning on and off at a certain interval plus a couple of spikes caused by the heater and coffee maker :) At the end of the plot, you can see the electrical consumption going down due to the activation of the Grid Tie Solar system as the sun is just starting to shine from the east :) Pretty much you can do more analysis here due to the plot details provided by the 10 second sampling. One thing noticeable here is the the gradual decrease in power after the activation of the refrigerator compressor. Do you know why that happens ? :)


 
 
Update: Here is a 5 day 10second sampling  continuous capture of the setup demonstrating stability in the capture :)
 


 

11/13/2013

EFERGY E2 CLASSIC FSK TRANSMISSION DECODING USING A RTL-SDR DONGLE AND RASPBERRY PI

Finally!  A complete working prototype of an EFERGY E2 CLASSIC Transmission decoder using a Raspberry Pi and RTL-SDR USB Dongle


Decoding an Efergy Energy Meter with RTL-SDR and a Raspberry Pi


 
 
 
It is now possible to capture those 10s to 20s power consumption samples or Efergy E2 Transmission raw data through use of a RTL-SDR USB dongle connected to a Raspberry Pi. The Rspi runs on a fedora Linux OS with the C code decoding software installed.
 
Here are a couple of sample screenshots where the app reads data from the dongle using rtl_fm and a C program that decodes the baseband data and displays the computed values   in CSV format;
 












 











 




 Output data is printed in CSV format and can be captured and saved for excel use such as this one ;
 

 

The source code can be downloaded here,

A more detailed writeup of the software decoding can be viewed at Gough's Tech Zone