Barometer (external)


Support for external barometers will be released with Copter-3.6.1. The instructions below have only been verified for the Drotek MS5611 barometer. The Adafruit BMP280 has not been verified to work yet.


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


On the top of the Drotek MS5611 board, the “I2C” jumper should be soldered. Look for “I2C/SPI” written on the board.

  • GND_PROBE_EXT to 4 for the Drotek MS5611 or 2 for the Adafruit BMP280. 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 they will be visible (once this issue is resolved) on the Flight Data >> Status tab, look for “press_abs2” and “press_temp2”.

Mission Planner’s MAVLink Inspector can also be used to view the data. From the Flight Data screen press Ctrl-F, then push the “MAVLink In” button and then expand the view and look for SCALED_PRESSURE2.