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Sensor Hardware & Setup

This section describes the mandatory and optional sensors and their setup/configuration.


PX4-based systems use sensors to estimate vehicle state, which is needed for stabilization and to enable autonomous control. Vehicle state information includes: position/altitude, heading, speed, airspeed, orientation (attitude), rates of rotation in different directions, battery level, and so on.

PX4 minimally requires a gyroscope, accelerometer, magnetometer (compass), and barometer to measure the above states. Fixed-wing and VTOL-vehicles should also include an airspeed sensor. A GPS or other positioning system is needed to enable all automatic modes, and some manual/assisted modes.

Pixhawk Series flight controllers already have the minimum set of sensors (other controller platforms often do too). Additional/external sensors can be attached to the controller — an external GPS and compass are recommended, along with an airspeed sensor for VTOL and Fixed wing vehicles.

Sensor Topics

Mandatory (included in Pixhawk series FCs):


  • Airspeed Sensors — Measures airspeed. Highly recommended for VTOL and Fixed-wing as they are the only mechanism to detect stall.
  • GNSS (GPS) — Measures global position. Needed for missions, and some other automatic and manual/assisted modes.
  • RTK GNSS (GPS) — GNSS with centimetre-level accuracy. Some setups also allow heading to be determine from GNSS rather than a magnetometer.


  • Distance Sensors (Rangefinders) — Measures distance to target. Aids landing, object avoidance, and terrain following.
  • Optical Flow — Estimates velocity using a downward facing camera and a downward facing distance sensor. Enables a more accurate position lock than GPS alone, and can be used indoors when no GPS signal is available.
  • Tachometers (Revolution Counters) — Only used for logging.

Other optional: