pyrtlsdr is a simple Python interface to devices supported by the RTL-SDR project, which turns certain USB DVB-T dongles employing the Realtek RTL2832U chipset into low-cost, general purpose software-defined radio receivers. It wraps many of the functions in the librtlsdr library (including asynchronous read support), and also provides a more Pythonic API.

##Installation

pyrtlsdr can be installed by downloading the source files and running

$ python setup.py install

This will install the python wrapper around librtlsdr. You will need to build librtlsdr from source yourself.

A simpler installation can be done by passing the argument --simple-install. This downloads/installs librtlsdr libraries and rtl-sdr executables in the package installation directory. However, the installed libraries may not be fully up to date.

$ python setup.py install --simple-install

All functions in librtlsdr are accessible via librtlsdr.py and a Pythonic interface is available in rtlsdr.py (recommended). Some documentation can be found in docstrings in the latter file.

Simple way to read and print some samples:

from rtlsdr import RtlSdr

sdr = RtlSdr()

# configure device
sdr.sample_rate = 2.048e6  # Hz
sdr.center_freq = 70e6     # Hz
sdr.freq_correction = 60   # PPM
sdr.gain = 'auto'

print(sdr.read_samples(512))

Plotting the PSD with matplotlib:

from pylab import *
from rtlsdr import *

sdr = RtlSdr()

# configure device
sdr.sample_rate = 2.4e6
sdr.center_freq = 95e6
sdr.gain = 4

samples = sdr.read_samples(256*1024)

# use matplotlib to estimate and plot the PSD
psd(samples, NFFT=1024, Fs=sdr.sample_rate/1e6, Fc=sdr.center_freq/1e6)
xlabel('Frequency (MHz)')
ylabel('Relative power (dB)')

show()

Resulting plot here.

See the files 'demo_waterfall.py' and 'test.py' for more examples.

Two new submodules are available for testing: rtlsdraio, which adds native Python 3 asynchronous support (asyncio module), and rtlsdrtcp which adds a TCP server/client for accessing a device over the network. See the respective modules in the rtlsdr folder for more details and feel free to test and report any bugs!

####rtlsdraio Note that the rtlsdraio module is automatically imported and adds stream() and stop() methods to the normal RtlSdr class. It also requires the new async/await syntax introduced in Python 3.5+.

The syntax is basically:

async def streaming():
 sdr = RtlSdr()
 
 async for samples in sdr.stream():
  # do something with samples
  # ...
  
  # to stop streaming:
  sdr.stop()
  
 # done
 sdr.close()
 
asyncio.get_event_loop().run_until_complete(streaming())

• Windows/Linux/OSX
• Python 2.7.x/3.3+
• librtlsdr (builds dated after 5/5/12)
• Optional: NumPy (wraps samples in a more convenient form)

matplotlib is also useful for plotting data. The librtlsdr binaries (rtlsdr.dll in Windows and librtlsdr.so in Linux) should be in the pyrtlsdr directory, or a system path. Note that these binaries may have additional dependencies.

There are a few remaining functions in librtlsdr that haven't been wrapped yet. It's a simple process if there's an additional function you need to add support for, and please send a pull request if you'd like to share your changes.

• Some operating systems (Linux, OS X) seem to result in libusb buffer issues when performing small reads. Try reading 1024 (or higher powers of two) samples at a time if you have problems.

• If you're having librtlsdr import errors:

  • Windows: Make sure all the librtlsdr DLL files (rtlsdr.dll and libusb-1.0.dll) are in your system path, or the same folder as this README file. Also make sure you have all of their dependencies (e.g. the Visual Studio runtime files). If rtl_sdr.exe works, then you should be okay. Also note that you can't mix the 64 bit version of Python with 32 bit builds of librtlsdr, and vice versa.
  • Linux: Make sure your LD_LIBRARY_PATH environment variable contains the directory where the librtlsdr.so.0 library is located. You can do this in a shell with (for example): export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib. See here for more details.

All of the code contained here is licensed by the GNU General Public License v3.

Credit to dbasden for his earlier wrapper python-librtlsdr and all the contributers on GitHub.

Copyright (C) 2013 by Roger https://github.com/roger-