librtlsdr (trackIT Systems fork): RTL2832U SDR driver and tools with Debian packages for Raspberry Pi OS

rtl-sdr turns your Realtek RTL2832 based DVB dongle into a SDR receiver. This repository contains the driver library librtlsdr and command line tools (rtl_test, rtl_sdr, rtl_fm, rtl_tcp, rtl_power, ...).

This is the librtlsdr used by tsOS-vhf. It adds individual gain stage control for R820T/R828D tuners, an extended tuner bandwidth handling and more compared to the original osmocom/steve-m sources, see README_improvements.md for the list of improvements, README.rtlfm_cmdfile for scanning with rtl_fm and README.rtlsdr_rpc for using a dongle from a remote host.

trackIT Systems fork

This fork continues the community fork librtlsdr/librtlsdr (v0.9.0, last commit 2024-03-22; that fork itself is a hard fork of steve-m/librtlsdr and appears to be inactive), because our software depends on its additions, e.g. rtlsdr_set_tuner_gain_ext() for the individual R820T/R828D gain stages, the extended tuner bandwidth handling and the GPIO/dithering API used by pyrtlsdr.

Policy: we maintain this fork ourselves and selectively port changes, either from steve-m/librtlsdr (e.g. stability fixes) or from the community fork. We do not merge wholesale. Ported commits are cherry-picked with -x so the origin stays visible in the log.

Versions: semantic versioning that continues the community lineage (v0.9.0 -> v0.9.1 -> ...). The Debian package version is derived from git describe, see below. (The tag v2.1.0 and the v2.0.x tags in this repository belong to other lineages and are not releases of this fork.)

Changes compared to the community fork

change	origin
fall back to userspace buffers if the Linux usbfs mmap() bug is present (zero-copy stays enabled)	steve-m f68bb2f
fix application hang on USB transfer errors: rtlsdr_read_async() returns -1 if the device is lost, rtl_fm terminates	steve-m 65f0658
add the missing 48.3 dB step to the tuner gain list (steve-m#110)	own
Debian packaging fixes, scripts/build-deb.sh and GitHub Actions build for Raspberry Pi OS	own

Reviewed steve-m/librtlsdr commits that are not ported

Reviewed up to steve-m v2.0.3 (2026-08-12).

commit	reason
81833a1 zero-copy disabled by default	we run with zero-copy (tsOS-vhf lifts the usbfs memory limit for it)
2659e2d, 5e73f90, 142325a	Windows-only sleep, libusb < 1.0.9 workaround, SIGPIPE in the command line tools; not needed
d81ef9a, e04c42c	FC0012 tuner only
d794155, f5978e8, 2acb75c, 0b64f07	tuner_r82xx.c was rewritten in the community fork (own PLL and shadow register handling); these do not apply
138cd05, 0204c9c RTL-SDR Blog V4 upconverter switch / V4L	only relevant for Blog V4 dongles; port when needed
CMake, Windows, macOS, OpenBSD, Debian metadata, rtl_tcp IPv6	not relevant for this fork

Reviewing upstream changes

git remote add upstream https://github.com/steve-m/librtlsdr.git
git fetch upstream
git cherry community-fork upstream/master   # '+' = commit not (yet) in the community fork
git cherry-pick -x <commit>

The branch community-fork is the unmodified state of the community fork this fork started from. The branch upstream-based holds an earlier experiment with this fork based on steve-m 2.0.3 (not maintained).

Install on Raspberry Pi OS / Debian (arm64)

Packages are built for Debian 13 (trixie), which Raspberry Pi OS is based on. Download the .deb files from the latest release and install them:

sudo apt install ./librtlsdr0_*.deb ./rtl-sdr_*.deb              # library and tools
sudo apt install ./librtlsdr-dev_*.deb                           # additionally, for development

• librtlsdr0 contains the library and the udev rules (/usr/lib/udev/rules.d/60-librtlsdr0.rules), rtl-sdr the command line tools, librtlsdr-dev headers, static library and pkg-config file.
• rtl-sdr and librtlsdr-dev replace the packages of the same name from Debian (2.0.x). The library has the soname librtlsdr.so.0 and therefore does not clash with Debian's librtlsdr2. Debian's version numbers are higher, so hold our packages if the system has access to the Debian repositories: sudo apt-mark hold librtlsdr0 rtl-sdr librtlsdr-dev.
• If the kernel DVB driver claims the dongle (rtl_test reports usb_claim_interface error -6), blacklist it, see Setup for SDR only use below.

Check the installation with a dongle plugged in:

rtl_test -t

Build from source

prerequisites

development tools have to be installed:

sudo apt-get install build-essential cmake git

install the libusb-1.0 development package:

sudo apt-get install libusb-1.0-0-dev

retrieve the sources

git clone https://github.com/trackIT-Systems/librtlsdr.git
cd librtlsdr

The master branch is the maintained one. Releases are tags vX.Y.Z.

build

run cmake and start compilation. cmake will accept some options, e.g.

• -DINSTALL_UDEV_RULES=ON, default is OFF
• -DDETACH_KERNEL_DRIVER=ON, default is OFF
• -DPROVIDE_UDP_SERVER=ON, default is OFF
• -DWITH_RPC=ON, default is OFF
• -DLINK_RTLTOOLS_AGAINST_STATIC_LIB=ON, default is OFF
• -DRTL_STATIC_BUILD=OFF, default is ON: for MINGW on WIN32

all cmake options are optional

mkdir build && cd build
cmake ../ -DINSTALL_UDEV_RULES=ON
make

install

setup into prefix, usually will require sudo:

sudo make install
sudo ldconfig

quick local build for testing (no install, no package)

cmake -S . -B build && cmake --build build
build/src/rtl_test -t

(needs libusb: brew install libusb or apt install libusb-1.0-0-dev)

Build the Debian packages

The packages are built with the packaging in debian/ inside a debian:trixie container, so Docker is the only requirement, on macOS, Linux and in CI:

scripts/build-deb.sh          # packages end up in ./dist

DEB_IMAGE (default debian:trixie), DEB_PLATFORM (e.g. linux/arm64) and OUT can be set to change the target. The package version is derived from git describe: tag v0.9.1 -> 0.9.1, later commits -> 0.9.1+gitN.<hash>, uncommitted changes add +dirty.

Continuous integration and releases

GitHub Actions (.github/workflows/deb.yml) runs scripts/build-deb.sh on an arm64 runner for every push and pull request and uploads the packages as an artifact. Pushing a tag vX.Y.Z additionally creates a GitHub release with the .deb files attached.

Only the Debian packages are built and tested. The scripts for cross-building for Windows (cross_build_mingw32.sh, cross_build_mingw64.sh) and the macOS/Windows build files are inherited from the community fork and are not tested by us.

For more information see:

http://superkuh.com/rtlsdr.html

https://osmocom.org/projects/rtl-sdr/wiki/Rtl-sdr

Setup for SDR only use - without DVB compatibility:

• a special USB vendor/product id got reserved at http://pid.codes/ : 0x1209/0x2832
• for such devices the linux kernel's DVB modules are not loaded automatically, thus can be used without blacklisting dvb_usb_rtl28xxu below /etc/modprobe.d/
• this allows to use a second RTL dongle for use with DVB in parallel
• the IDs can be programmed with 'rtl_eeprom -n' or 'rtl_eeprom -g realtek_sdr'
• for permanent blacklisting you might check/call following from the clone git directory ./install-blacklist.sh

Contributing

Pull requests are welcome, please open them against master.

• Changes that originate from steve-m/librtlsdr or the community fork are ported with git cherry-pick -x <commit> (see Reviewing upstream changes); add new reviewed-but-skipped commits to the table above.
• Check a change locally with scripts/build-deb.sh; CI runs the same script.
• A release is a tag vX.Y.Z on master; CI builds the packages and attaches them to the release.