BrainRE1, General

Meet RE1-Baro: Barometer add-on for RE1

Do you sometimes wonder how high you are? Everyone does, especially when flying FPV. 

This is why we created "RE1-Baro", a barometer add-on for the BrainFPV RE1 flight controller. The add-on uses a barometer to measure the pressure of the ambient air, from which RE1 then calculates the altitude. When we created BrainFPV RE1, we designed it with racing in mind, so we only added the sensors essential for racing, i.e., a 3-axis gyroscope and a 3-axis accelerometer. At the same time, we wanted RE1 to be extendable, so we added an extension port with high speed interfaces (SPI, I2C), as well as general purpose signals. RE1-Baro is the first add-on for RE1 that makes use of the extension port and so can directly stacked on top of RE1 without any wiring, making it easy to use and keeping your build neat and clean.

Why use a barometer? 

  • So you can display the altitude in the OSD to always know how high you are.
  • You can use the altitude-hold flight mode.
  • Go all out and combine it with a GPS and an I2C compass to make RE1 fully navigation capable (position hold, loiter, return-to-home, waypoints).

Note that altitude-hold and navigation features are only supported in dRonin (they may be available in Betaflight, but support is much less mature). The features in dRonin are also somewhat experimental. Some information can be found in the dRonin WIKI and we will write future blog posts about it. 



Installing the barometer add-on couldn't be easier:

1: Place the spacers and foam.


2: Position the add-on and craefully press down with your finger.
You will hear a "click" when the connector mates.

3: Use the screws to hold the add-on in place. Done :).

Enable the Barometer

Depending on whether you use dRonin or Betaflight, different steps are needed to enable the barometer. 

dRonin: Under "Hardware" in the dRonin GCS set "I2CExtBaro" to "BMP280".  Click "Save" and reboot RE1.

Betaflight: In the Betaflight configurator in the "Configuration" tab, enable "Barometer" (under "System Configuration"). Then click on "Save and Reboot". Note: the barometer is only supported in Betaflight version v3.0.1-BRAIN-2 and newer.


  • Barometer: Bosch Sensortec BMP280 connected using I2C.
  • Included: RE1 - Baro add-on, 2.5mm spacers (2x), 8mm screws (2x), foam.
  • Size: 36mm x 18mm. 
  • Vertical space required: 3.5mm (makes stack 3.5mm taller than without add-on)

Related Posts

Leave a Reply