Version 3.2

Version 3.2 is the most recent stable firmware.

This release make a huge difference in flight stability and in automatic flying.

This firmware is suitable only for VRBRAIN 4 and VRBRAIN 4.x boards without the SD card reader.

If you have an SD card, you should use the new 3.2 with NuttX operating system as you will enjoy Logs on SD, terrain following and many other future features that will require the use of an SD card.

To make life easier, we decided to use a bootloader to upload the new release, the same used for VRBRAIN 5, so you would need to use DFU uploader only once and then proceed with the mission planner software


  • Automatic external/internal compass recognition. No need to use a special firmware (not available for OCTA or OCTA-QUAD).
  • GPS port configurable via mission planner on 2 serial ports (internal connector or external connector near input rail). No need to upload a special firmware.
  • 8 PWM inputs, SBUS support with adapter cable, PPMSUM.
  • ALL automatic functions of the APM: Copter 3.2 (ROI, GUIDED,FOLLOW ME etc.).
  • Up to 12 outputs if using PPMSUM or SBUS.
  • EKF support. Enable or disable EKF logging using EKF_LOG_ENABLE parameter.
  • Logging on 2 Mbit high speed dataflash.
  • Update via mission planner without BOOT jumper disconnect.

Known issues:

  • Only one compass at a time (at the moment).
    You can either use the internal or external compass.
    You need to redo calibration and reconfiguration after compass change.
  • No multiple GPS supported (at the moment).
  • No multiple IMU supported.
  • The use of external sensors such as OptFlow, Sonar, Airspeed etc. has not been tested.
  • No terrain following or infinite logs on SD card.

Instructions to install the firmware:

Firmware ver. 3.2 – VRBRAIN 4.0  and  VRBRAIN 4.5 without SD card reader
  1. Download the bootloader dfu file from here: vrbrainv40_bl.dfu
  2. Download the firmware for your specific frame:

TRI CopterArduCopter-vrbrain-v40-tri.vrx

QUAD Copter: ArduCopter-vrbrain-v40-quad.vrx

HEXA Copter: ArduCopter-vrbrain-v40-hexa.vrx

OCTA Copter: ArduCopter-vrbrain-v40-octa.vrx

OCTA-QUAD Copter: ArduCopter-vrbrain-v40-octa-quad.vrx

Y6 Copter: ArduCopter-vrbrain-v40-y6.vrx

SINGLE Copter: ArduCopter-vrbrain-v40-single.vrx

COAX Copter: ArduCopter-vrbrain-v40-coax.vrx

Plane: ArduPlane-vrbrain-v40.vrx

Steps 1 to 3 are only for a first time setup, after you successfully uploaded the bootloader, follow only steps 4 to 9!
  1. Download and Install the drivers for the VRBRAIN boards from this link.
  2. upload the bootloader file you just downloaded (vrbrainv40_bl.dfu) with the DfuSe Demonstration utility as you would do with standard firmware (follow the instructions). in:
  3. Attach the USB and you will notice yellow led blinking fast.
  4. Now open Mission Planner, go to “INITIAL SETUP”–>Install Firmware–>Load Custom Firmware.
  5. Choose the file you have just downloaded eg. ArduCopter-vrbrain-v40-quad.vrx and click “OK”.
  6. If a Message box appear, follow the instructions: disconnect the board from USB, click OK and then reconnect the board.
  7. If no message appears and you see a “connecting” unplug the board and plug it back again.
  8. After upload, disconnect and reconnect the board.
  9. Done!

First time setup:

If you upgraded from 3.1.16 it is a good choice to Save your parameters onto a file, erase all parameters, and load them back, this to ensure there is no overwrite.


If you have an external compass and not using OCTA or OCTA-QUAD frames, you can attach the compass to motors output 7 & 8. The firmware will automatically detect the compass and set the COMPASS_EXTERNAL parameter to 1. If the parameter is still 0, try to invert the cables.

Once you have an external compass you should set the COMPASS_ORIENTATION to 12 (assuming you are using 3DR or VR GPS with exteranl compass).

If you disconnect the compass on next reboot you will have the internal one active.

If you change from internal to external compass, you NEED to redo calibration!


Normally GPS will be connected on the internal rail or on the internal GPS connector. If you need to connect it to the external rail, you need to set the parameter GPS_PORT = 2.

This will enable you to connect the GPS on the pins labeled TELEM on the INPUT rail.


Telemetry can be connected to the SER1 pins near the external GPS port.

A second telemetry can be connected on the internal GPS rail if GPS_PORT = 2 or on the TELEM pins if GPS_PORT = 1.

EKF logs

Because EKF logs consume a lot of space on the dataflash, we have added a new parameter to enable them. By default the EKF logs are disabled.

EFK_LOG_ENABLE = 1 enables logs.

EKF_LOG_ENABLE = 0 disable EKF logging.

3 comments on “Version 3.2

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