
  rtl-wmbus - Software Decoder for Wireless-M-Bus with RTL-SDR
  ------------------------------------------------------------

rtl-wmbus is a software-defined radio receiver for Wireless-M-Bus. It is
written in plain C and uses RTL-SDR to interface with RTL2832-based hardware.

Wireless-M-Bus is the wireless version of M-Bus ("Meter-Bus", http://www.m-bus.com),
which is an European standard for remote reading of smart meters.

The primary purpose of rtl-wmbus is experimenting with digital signal
processing and software radio. rtl-wmbus can be used on resource constrained
devices such Raspberry Pi Zero or Raspberry PI B+ overclocked to 1GHz.
Any Android based tablet will do the same too.

rtl-wmbus provides:
 * FSK demodulating
 * clock recovery
 * mode T1 and mode C1 packet decoding

rtl-wmbus requires:
 * Linux or Android
 * C99
 * supported DVB-T receiver
 * RTL-SDR library for Linux: http://sdr.osmocom.org/trac/wiki/rtl-sdr or
 * (optional, only for android builds) RTL-SDR library port for Android: https://github.com/martinmarinov/rtl_tcp_andro-

For the latest version, see https://github.com/xaelsouth/rtl-wmbus


  Installing
  ----------

The Osmocom RTL-SDR library must be installed before you can build
rtl-wmbus. See http://sdr.osmocom.org/trac/wiki/rtl-sdr for more
information. RTL-SDR library for Android would be installed via
Google Play.

To install rtl-wmbus, download, unpack the source code and go to the
top level directory. Then use one of these three options:

 $ make debug # (no optimization at all, with debug options)

 $ make release # (-O3 optimized version, without any debugging options)

 $ make pi1 # (Raspberry Pi optimized version, without any debugging options,
               will build on RasPi1) only

Before building Android version the SDK and NDK have to be installed.
See androidbuild.bat for how to build.

   Usage
   -----
Shown using "release"-version:

 To save IQ-stream on disk and decode them off-line:

 $ rtl_sdr samples.bin -f 868.9M -s 1600000

 $ cat samples.bin | build/rtl_wmbus

 To run continuously:

 $ rtl_sdr -f 868.9M -s 1600000 - 2>/dev/null | build/rtl_wmbus

 To count "good" (no 3 out of 6 errors, no checksum errors) packets:

 $ cat samples.bin | build/rtl_wmbus 2>/dev/null | grep "[T,C]1;1;1" | wc -l

Carrier-frequency given at "-f" must be set properly. With my DVB-T-
Receiver I had to choose carrier 50kHz under the standard of 868.95MHz. 
Sample rate at 1.6Ms/s is hardcoded and cannot be changed.

samples2.bin is a "life" example with two devices received.

On Android first the driver must be started with options given above.
IQ-data goes to a port which is would be already set by driver settings.
Use get_net to get IQ-data into rtl_wmbus.

  License
  -------

Copyright (c) 2017 <xael.south@yandex.com>

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:

1. Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   documentation and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.
