ria-toolkit-oss/docs/source/sdr_guides/rtlsdr.rst

.. _rtl:

RTLSDR
======

RTL-SDR (RTL2832U Software Defined Radio) is a low-cost USB dongle originally designed for digital TV reception
that has been repurposed as a wideband software-defined radio. RTL-SDR devices are popular for hobbyist use due to
their affordability and wide range of applications.

The RTL-SDR is based on the Realtek RTL2832U chipset, which features direct sampling and demodulation of RF
signals. These devices are commonly used for tasks such as listening to FM radio, monitoring aircraft traffic
(ADS-B), receiving weather satellite images, and more.

Supported Models
----------------
    - Generic RTL-SDR Dongle: The most common variant, usually featuring an R820T or R820T2 tuner.
    - RTL-SDR Blog V3: An enhanced version with additional features like direct sampling mode and a bias tee for
      powering external devices.

Key Features
------------
    - Frequency Range: Typically from 24 MHz to 1.7 GHz, depending on the tuner chip.
    - Bandwidth: Limited to about 2.4 MHz, making it suitable for narrowband applications.
    - Connectivity: USB 2.0 interface, plug-and-play on most platforms.
    - Software Support: Compatible with SDR software like SDR#, GQRX, and GNU Radio.

Limitations
-----------
    - Narrow bandwidth compared to more expensive SDRs, which may limit some applications.
    - Sensitivity and performance can vary depending on the specific model and components.
    - Requires external software for signal processing and analysis.

Set up instructions (Linux, Radioconda)
---------------------------------------

1. Activate your Radioconda environment:

  .. code-block:: bash

    conda activate <your-env-name>

2. Purge drivers:

If you already have other drivers installed, purge them from your system.

  .. code-block:: bash

    sudo apt purge ^librtlsdr
    sudo rm -rvf /usr/lib/librtlsdr* 
    sudo rm -rvf /usr/include/rtl-sdr* 
    sudo rm -rvf /usr/local/lib/librtlsdr* 
    sudo rm -rvf /usr/local/include/rtl-sdr* 
    sudo rm -rvf /usr/local/include/rtl_* 
    sudo rm -rvf /usr/local/bin/rtl_*

3. Install RTL-SDR Blog drivers:

  .. code-block:: bash

    sudo apt-get install libusb-1.0-0-dev git cmake pkg-config build-essential
    git clone https://github.com/osmocom/rtl-sdr 
    cd rtl-sdr
    mkdir build
    cd build
    cmake ../ -DINSTALL_UDEV_RULES=ON
    make
    sudo make install
    sudo cp ../rtl-sdr.rules /etc/udev/rules.d/
    sudo ldconfig

4. Blacklist the DVB-T modules that would otherwise claim the device:

  .. code-block:: bash
    sudo ln -s $CONDA_PREFIX/etc/modprobe.d/rtl-sdr-blacklist.conf /etc/modprobe.d/radioconda-rtl-sdr-blacklist.conf
    sudo modprobe -r $(cat $CONDA_PREFIX/etc/modprobe.d/rtl-sdr-blacklist.conf | sed -n -e 's/^blacklist //p')

.. note::

   In addition to the Radioconda blacklist file, some systems also require
   manually blacklisting the following DVB-T modules to prevent them from
   claiming the device:

     - ``dvb_usb_rtl28xxu``
     - ``rtl2832``
     - ``rtl2830``

   Add these entries to ``rtlsdr.conf`` (or create the file at
   ``/etc/modprobe.d/rtlsdr.conf``) if they are not already present.

5. Install a udev rule by creating a link into your radioconda installation:

  .. code-block:: bash
    sudo ln -s $CONDA_PREFIX/lib/udev/rules.d/rtl-sdr.rules /etc/udev/rules.d/radioconda-rtl-sdr.rules
    sudo udevadm control --reload
    sudo udevadm trigger

Further Information
-------------------
    - `RTL-SDR Official Website <https://www.rtl-sdr.com/>`_
    - `RTL-SDR Documentation <https://www.rtl-sdr.com/rtl-sdr-quick-start-guide/>`_