Use rtl-sdr to receive EnergyCount 3000 transmissions


Software receiver for EnergyCount 3000

This module allows you to receive and decode radio transmissions from EnergyCount 3000 energy loggers using a RTL-SDR supported radio receiver and the GNU Radio software defined radio framework.

EnergyCount 3000 transmitters plug between a device and an AC power outlet and monitor electrical energy usage. They transmit a packet with a status update every 5 seconds on the 868 MHz SRD band. Reported values include id of the device, current and maximum seen electrical power, total energy used and device on time.

Module content

The module exports a class that represents the radio receiver. You provide it with a callback function that is called each time a new status update is received:

def callback(state):
    print state

my_ec3k = ec3k.EnergyCount3K(callback=callback)

while not want_stop:
    print "Noise level: %.1f dB" % (my_ec3k.noise_level,)


The example above prints out the following on each status update:

id              : ....
time total      : .... seconds
time on         : .... seconds
energy          : .... Ws
power current   : .... W
power max       : .... W
reset counter   : ....

You can also get the last received state by calling the get method on the EnergyCount3K object. See docstrings for details.

Also included is an example command-line client ec3k_recv that prints received packets to standard output.


You need the GNU Radio framework, rtl-sdr and the gr-osmosdr package.

Combination of versions last known to work:

  • GNU Radio release 3.7.5
  • rtl-sdr git commit d447a2e9 (2014-08-26)
  • gr-osmosdr git commit 48045b59 (2015-01-10)

For baseband decoding a pure Python implementation is included in this package ( and should work out of the box.

For more efficient decoding a C implementation can also be used. Obtain the source from the address below, compile it and make sure capture binary is in PATH. It should then get used automatically instead of the Python implementation.


Install ec3k as you would most other Python packages:

$ python install
$ python test

To try it out, run the example command-line client:

$ ec3k_recv

Please note that the receiver needs some time to adapt to the signal and noise level in your environment. It might take a few minutes before ec3k_recv prints out any decoded packets.

Known problems

Occasionally the GNU Radio pipeline isn't setup correctly. If this happens the noise level constantly stays at -90 dB and no packets are ever received. Restarting the program usually helps. Updating gr-osmosdr and rtl-sdr usually fixes this problem.

Stopping the receiver sometimes causes a segfault. Updating gr-osmosdr and rtl-sdr usually fixes this problem.


Please send patches or bug reports to <>


You can get a local copy of the development repository with:

git clone git://


ec3k, software receiver for EnergyCount 3000

Copyright (C) 2015 Tomaz Solc <>

Copyright (C) 2012 Gasper Zejn

Protocol reverse engineering:

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see <>.