MAVCONN library

It is mavlink connection and communication library used in MAVROS. Since 2014-11-02 it adopted to use outside from ROS environment by splitting to individual package and removing dependencies to rosconsole.

See the MAVROS documentation and the libmavconn API reference for more details.

Connection URL

Connection defined by URL. Just pass one of that URL to MAVConnInterface::open_url() and get connection object.

Supported schemas:

• Serial: /path/to/serial/device[:baudrate]
• Serial: serial:///path/to/serial/device[:baudrate][?ids=sysid,compid]
• Serial with hardware flow control: serial-hwfc:///path/to/serial/device[:baudrate][?ids=sysid,compid]
• UDP: udp://[bind_host][:port]@[remote_host][:port][/?ids=sysid,compid]
• UDP broadcast until GCS discovery: udp-b://[bind_host][:port]@[:port][/?ids=sysid,compid]
• UDP broadcast (permanent): udp-pb://[bind_host][:port]@[:port][/?ids=sysid,compid]
• TCP client: tcp://[server_host][:port][/?ids=sysid,compid]
• TCP server: tcp-l://[bind_port][:port][/?ids=sysid,compid]

Note: ids from URL overrides ids given by system_id & component_id parameters.

Dependencies

Same as for mavros:

• Linux host
• Asio library ( https://think-async.com/Asio/ )
• console-bridge library
• compiler with C++20 support

Shared io_service (optional)

By default each connection owns and runs its own asio::io_service thread. For multi-connection setups you can provide a shared asio::io_service and run it from your own thread pool.

#include <asio.hpp>
#include <mavconn/interface.hpp>

asio::io_service shared_io;
auto work = std::make_unique<asio::io_service::work>(shared_io);
std::jthread io_thread([&]() { shared_io.run(); });

auto conn = mavconn::MAVConnInterface::open_url(
  "udp://0.0.0.0:14555@127.0.0.1:14550",
  1, mavconn::MAV_COMP_ID_UDP_BRIDGE,
  [](const mavlink::mavlink_message_t *, mavconn::Framing) {},
  {},
  &shared_io);

conn->close();
work.reset();
shared_io.stop();

License

Licensed under terms of LGPLv3, BSD, or GPLv3.

Changelog for package libmavconn

2.17.0 (2026-11-11)

• Merge pull request #2357 from zekesarosi/feat/rt-sched-fifo-upstream mavros: optional SCHED_FIFO for router io and executor threads
• Merge branch 'ros2' into feat/rt-sched-fifo-upstream
• Merge pull request #2348 from zekesarosi/fix/mavconn-lifecycle libmavconn: harden UDP/TCP/serial lifecycle
• mavros: optional SCHED_FIFO for router io and executor threads Add mavconn::utils::set_this_thread_sched_fifo(), which returns the error code from pthread_setschedparam(). The new rt_sched_fifo_priority parameter (mavros_node, mavros_router, UAS) defaults to 0, which leaves scheduling untouched and logs nothing. When set, it applies to the router io thread (now named mudp-io), the mavros_node executor and the UAS executor; executor worker threads are spawned by the spinning thread and inherit its policy. The router reads the parameter in its constructor, before it starts the io thread, so it is read-only; mavros_node forwards its value through NodeOptions parameter overrides instead of set_parameters().
• libmavconn: harden UDP/TCP/serial lifecycle - capture shared_from_this() in the initial asio::post so the first read/accept cannot run on a destroyed object - UDP: keep receiving on transient errors (ECONNREFUSED, ENETUNREACH, EHOSTUNREACH, EAGAIN) instead of closing the link - UDP: drop a datagram that fails to send with a transient error instead of retrying it forever and wedging tx_q
  • tests: close connections explicitly and lock the test fixture mutex
• Contributors: Vladimir Ermakov, Zeke Sarosi

2.16.0 (2026-09-27)

• Merge pull request #2290 from mavlink/fix-io-context libmavconn: fix IoContextRunner self-close lifetime and restart (fix #2275)
• libmavconn: fix IoContextRunner self-close lifetime and restart (fix #2275) On a shutdown initiated from the owned I/O thread (self-close), join_owned() detaches the worker thread. The runner then called restart() while run() was still active on that thread (undefined behaviour) and, after the worker detached, could be destroyed while the thread still wrote is_running_. Move the io_context, work guard, and is_running flag into a heap-shared State that the worker thread also holds. The worker restarts the io_context only after run() returns, and the State (and thus the io_context) survives even if the owning connection is destroyed before the detached thread completes.
• Merge pull request #2289 from mavlink/check-cbg plugins: fix cmd/command service deadlocks and const shared_ptr deprecation warnings
• libmavconn: consume nodiscard result in baudrate test The serial baudrate regression test calls open_url_no_connect() expecting it to throw DeviceError; the [[nodiscard]] return was left unconsumed, producing -Wunused-result warnings. Capture it in a [[maybe_unused]] variable.
• Merge pull request #2287 from christophebedard/christophebedard/fix-libmavconn-missing-ament-cmake-google-benchmark-dep
• Add missing test_depend on ament_cmake_google_benchmark to libmavconn It's used in tests since #2256, but it wasn't declared as a (test) dependency, resulting in build failures on the ROS 2 buildfarm: https://build.ros2.org/view/Hbin_uJ64/job/Hbin_uJ64__libmavconn__ubuntu_jammy_amd64__binary/160/console ` 23:58:37 CMake Error at CMakeLists.txt:117 (find_package): 23:58:37 By not providing "Findament_cmake_google_benchmark.cmake" in 23:58:37 CMAKE_MODULE_PATH this project has asked CMake to find a package 23:58:37 configuration file provided by "ament_cmake_google_benchmark", but CMake 23:58:37 did not find one. 23:58:37 23:58:37 Could not find a package configuration file provided by 23:58:37 "ament_cmake_google_benchmark" with any of the following names: 23:58:37 23:58:37 ament_cmake_google_benchmarkConfig.cmake 23:58:37 ament_cmake_google_benchmark-config.cmake`
• Contributors: Christophe Bedard, Vladimir Ermakov

2.15.1 (2026-08-22)

• libmavconn: fix serial baudrate parsing above uint16 url_parse_host hardcoded a uint16 port limit and error label, which rejected serial baudrates above 65535 (e.g. 921600) with a misleading 'invalid port value' error. Make the value range and field name configurable and allow baudrate to use the full int range. Adds a regression test covering a high valid baudrate and invalid zero/non-numeric baudrates. Fix #2265
• Merge pull request #2260 from mavlink/fix-deprecations Fix deprecations
• libmavconn: fix deprecated literal operator whitespace
• libmavconn: avoid -Wformat-security in format() with no args
• Contributors: Vladimir Ermakov

2.15.0 (2026-08-08)

• Merge pull request #2259 from mavlink/docs-refresh docs: refresh, refactor extractor

• docs: refresh subpackage READMEs

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