Barometer (external)


This page is a work-in-progress and the instructions below have not been completely verified to be correct


Most flight controllers include a barometer directly on the flight controller but attaching an external barometer can be useful in order to place the barometer away from air pressure disturbances.


Copter users can partially reduce the effect of air pressure disurbances by enabling Ground Effect Compensation

Where to Buy

Connecting and Configuring

Connect the barometer to the flight controller’s I2C port as shown below

../_images/baro-ms5611-pixhawk.jpg ../_images/baro-bmp280-pixhawk.jpg
  • GND_EXT_BUS to 1 for Pixhawk boards or 0 for Cubes. Other flight controllers will also be either 0 or 1. Reboot the flight controller after changing this parameter.
  • GND_PRIMARY to 1 to use the external barometer as the primary



Real-time pressure and temperature from the barometer are sent to the ground station. If using Mission Planner these values can be seen on the Flight Data >> Status tab, look for “press_abs” and “press_temp”.