PixHawk PX4: UBX Protocol & Paired Beacons | Marvelmind
Heading & Direction Tracking: How It Works
This technical guide explains Marvelmind's MMSW0003 UBX protocol license, which enables PixHawk with PX4 to stream location data from a mobile Super-Beacon and replace u-Blox compass readings with heading information from Paired Beacons. The system uses I2C communication to provide seamless integration, allowing autonomous drones and indoor robots to navigate accurately without relying on traditional magnetometers that fail indoors.
Transcript
This technical guide explains Marvelmind's MMSW0003 UBX protocol license, which enables PixHawk with PX4 to stream location data from a mobile Super-Beacon and replace u-Blox compass readings with heading information from Paired Beacons. The system uses I2C communication to provide seamless integration, allowing autonomous drones and indoor robots to navigate accurately without relying on traditional magnetometers that fail indoors.
0:01 Hello colleagues. I will be talking about paired beacons for drones, particularly for PX4 on Pixhawk with u-blox GPS. So what we do first of all, we always recommend using the paired beacons configurations for drones and not to use the magnetometer. The issue is that in the building there are always ferrous magnetic materials, shelves, or electromagnetic fields due to current, and the magnetic field of the earth is distorted. So effectively, you cannot use a magnetometer indoors. But how to know the direction? Because you want to know not only the location of your drone but also where the drone is facing. So our solution is the paired beacons. Of course, it's better to have the base as large as possible because
1:01 each of the beacons calculates the position with some precision. In our case, plus or minus two centimeter precision. So it means that if this location and this location is known with plus or minus precision, then in the worst case it would be either like this or like this. So you will have several degrees in accuracy in direction when the location of both beacons are measured. So it means that if you want high precision or high accuracy of direction, you need either to increase even further the precision of positioning or to increase the base. Now, further to increase position is hardly possible because we already give you two plus or minus two centimeter precision, and often you cannot increase the base as well because it's limited by the size of your drone. So in our case, that's their maximum recommended, and that would give around, I don't
2:00 remember, around four degrees accuracy of direction. But then how to feed it into Pixhawk? This nice GPS is getting connected, so you are getting the direction. Instead of GPS, you are getting their location to this pin. But at the same time, we do a nice trick. We actually emulate the IMU data from u-blox sensor, and that means that the Pixhawk actually believes that it is getting their magnetometer data from u-blox. But in fact, it's getting their location and direction magnetometer data as direction from our paired beacons. And that feature is enabled. So please check it. In this case, you can fly PX4 on Pixhawk with the paired beacons and use it for your autonomous drones. Thank you very much.
Video Contents
Key Takeaways
- MMSW0003 license enables mobile Super-Beacons to stream location data via UBX protocol directly to PixHawk controllers
- Paired Beacons configuration replaces unreliable indoor magnetometers with ultrasonic-based heading calculation
- I2C communication ensures plug-and-play compatibility with existing PX4 firmware stacks
- Centimeter-level indoor positioning accuracy enables autonomous drones, forklifts, and warehouse robots
- No PX4 firmware modifications required—PixHawk receives Marvelmind data as standard u-Blox compass signals
Relevant For: Developers Needing Heading & Angle Data
Roboticists and drone engineers integrating PixHawk flight controllers with PX4 firmware who need reliable indoor positioning and heading data without dependence on magnetic compasses. This solution solves the critical problem of magnetometer interference and unreliability in indoor environments where GPS is unavailable.
FAQ
Paired Beacon Direction Tracking System
PixHawk flight controllers running PX4 firmware require accurate heading and position data for autonomous indoor navigation. Marvelmind's MMSW0003 license solves a critical integration challenge by enabling a mobile Super-Beacon to broadcast location and directional data using the UBX (u-Blox) protocol—the industry standard for PixHawk communication. The license works with Marvelmind's Paired Beacons configuration, which calculates both location (X, Y, Z coordinates) and heading direction from ultrasonic ranging signals. Through I2C connectivity, the PixHawk receives this data as if it came from a standard u-Blox compass, eliminating the unreliability of magnetometers in indoor metal-rich environments like warehouses, factories, and research facilities. This approach maintains full compatibility with existing PX4 stacks while replacing failed or unavailable compass sensors. The Paired Beacons configuration provides centimeter-level positioning accuracy and reliable directional information, enabling autonomous indoor drones, forklifts, and mobile robots to operate safely without GPS or magnetic compass dependence.
Topics
Related Resources
📍 Need precise indoor positioning for your project?