PX4
PX4 Development Drones and Autopilots
ModalAI builds autopilots that run PX4 directly, and complete aircraft that arrive flying it. VOXL 2 and VOXL 2 Mini fuse a Linux companion computer and a PX4 flight controller onto one board, so the autonomy stack and the flight stack share a processor instead of talking across a wire.
Starling 2 Max
Starling 2 Max is our recommended starting point for PX4 development. It ships ready to fly on VOXL 2, running PX4 out of the box, with computer-vision dead reckoning for GPS-denied flight and 500 g of payload capacity for whatever you add.
Because it is the same VOXL 2 and the same PX4 build you would integrate yourself, work done on a Starling 2 Max moves onto your own airframe without a rewrite — the parameters, the tuning and the code all carry over.
voxl-px4
voxl-px4 is a wrapper around the QRB5165 build of PX4 that runs it as a Linux service on VOXL 2 and VOXL 2 Mini. ModalAI maintains its own PX4 fork so QRB5165 support lands ahead of upstream releases; versions follow v<upstream PX4 base>-<ModalAI revision>, for example v1.14.0-2.0.146. It integrates PX4 with the VOXL sensor suite and the modal pipe architecture used across the VOXL SDK.
voxl-vision-hub (formerly voxl-vision-px4) is the coordinator between the perception services and the autopilot. It forwards VIO as MAVLink odometry and fuses obstacle sensor data for collision avoidance, so the aircraft can fly without GPS — and it has grown well past a data relay, handling waypoint missions, AprilTag relocalization, in-flight horizon calibration and trajectory-following flight modes. It also underpins MAVROS and MAVSDK.
Ground Stations, MAVROS and MAVSDK
Because it is real PX4, the whole ecosystem works as you would expect:
- MAVROS — talk to PX4 from ROS 1 or ROS 2
- MAVSDK — control the vehicle from C++, Python or Swift
- PX4 parameters — upload and manage parameter sets, including from QGroundControl
- Flight controller configuration — the miscellaneous settings that are easy to miss
- VOXL ESCs with PX4 — closed-loop RPM control from the VOXL ESC Mini and VOXL ESC FPV
A Dronecode Member
ModalAI has been a Silver member of the Dronecode Foundation since 2019. Dronecode is the open-source foundation that stewards PX4, so the flight stack our hardware runs is one we help support rather than merely consume.
Documentation
Everything above is documented in full at docs.modalai.com, alongside HITL setup, tuning guides and the rest of the VOXL SDK. For the boards themselves, see VOXL.