pyrtlsdr 0.2.0

# Description

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 all the
functions in the [librtlsdr library](http://sdr.osmocom.org/trac/wiki/rtl-sdr) (including asynchronous read support),
and also provides a more Pythonic API.

# Usage

pyrtlsdr can be installed by downloading the source files and running `python setup.py install`, or using [pip](http://www.pip-installer.org/en/latest/) and
`pip install pyrtlsdr`.

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.

## Examples

Simple way to read and print some samples:

```python
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:

```python
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](http://i.imgur.com/hFhg8.png).

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

# Dependencies

* 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.

# Todo

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.

# Troubleshooting

* 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 in Windows, make sure all the DLL files 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.
* In Windows, you can't mix the 64 bit version of Python with 32 bit builds of librtlsdr.

# License

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

# Credit

Credit to dbasden for his earlier wrapper [python-librtlsdr](https://github.com/dbasden/python-librtlsdr) and all the
contributers on GitHub.

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