Hello, this is Aiden from the Marketing Team.

Today, I would like to introduce PX4 MAVLink-Python Programming, specifically focusing on the use of Python MAVLink libraries. Please note that this content is copyrighted by QUAD Drone Lab, and we kindly ask that you refrain from unauthorized distribution.

Using Python MAVLink Library

Overview

The pymavlink package includes language-specific generator modules that provide low-level functionality for encoding and decoding messages, as well as applying and verifying signatures.

The set of modules within the pymavlink package is as follows:

• \dialects\v20* and \dialects\v10*: These are the Dialect modules corresponding to each source XML message definition for MAVLink v2 and v1, respectively. Each dialect module includes:
• Constants for all enumerations and enum values defined in the XML file.
• A set of constants for message identifiers.
• Classes for each type of MAVLink message defined in the XML file.
• MAVLink classes that can be used to send and receive messages:
  • They feature _send and _decode functions for each message type.
  • They include methods for verifying and applying signatures.
  • They contain low-level methods for data compression and parsing.

pymavlink Module

• mavutil : MAVLink Utility Functions for Communication Link Setup, Message Reception/Decoding, and Periodic Tasks
• mavutil.mavlink_connection(device, baud, ...)Establishes a link to receive messages or send them over a channel (e.g., UDP, Serial, etc.). This function returns an object representing the connection. You can use:
  • Property for accessing the selected language/protocol module to encode and send mavmessages
  • setup_signing() for signature configuration
  • recv_match() for capturing messages with specific names or field values
• You can perform many other useful tasks through the connection, such as retrieving all autopilot parameters, accessing the last message received of each type, and obtaining autopilot telemetry, including the current flight mode or arming status.
• mavwp : Load/save waypoints, geofences, and rally points.
• mavparm : Load/save MAVLink parameter sets.
• mavextra : Useful functions for converting values and messages (e.g., meters/second to km/h, Euler angles to quaternions in radians, etc.).
• maveexpression (internal): MAVLink expression evaluation functions.

Generally, most developers use the mavutil module to set up and manage communication channels because it is very easy to get started. This module provides a simple mechanism for establishing links, sending and receiving messages, and querying several basic autopilot properties such as the currently active flight mode. It provides access to the modules used for encoding, decoding, and signing messages through the property (mav).

There are several key precautions you should be aware of when using mavutil:

• The link does not properly handle multiple systems running on the same port. If a multi-vehicle network is required, please refer to the source-system-filtering sample.
• This module is optimized for ArduPilot, and some functions may not work correctly with other autopilots.
• mavutil is still a relatively low-level MAVLink API. Support for the most common MAVLink microservices is also limited.

You do not necessarily have to use mavutil, but it contains a lot of useful code that you would otherwise have to write from scratch. In particular, the connection code and the methods for filtering incoming messages are useful for all types of autopilots.

B. Installing pymavlink

pip3 install pymavlink

pip3 install pymavlink

YouTube Class

This concludes our look at the second stage of PX4 MAVLink-Python Programming: using the Python MAVLink library. In the next post, we will return with a guide on how to Connect to your drone.

Author: Aiden, Marketing Team at QUAD Drone Lab

Date: February 24, 2026