Connect PX4FLOW to QGroundControl

I followed the document PX4FLOW Developer Guide, connected QGroundControl to PIXFLOW finally.

PX4FLOW data output in QGroundControl
PX4FLOW data output in QGroundControl

The picture above is output ofOPTICAL_FLOW.flow_x and flow_y

I have some questions when start:
Q: Connect Pixhawk or PX4FLOW to PC when upload firmware?
A: Connect FX4FLOW to PC using USB

Q:VIDEO_ONLY set to 1, butVideo Downlink in QGroundcontrol can’t show PXFLOW’s video output (use it to adjust focus only)
A:upgrade QGroundcontrol to version 2.2 or up

Qgroundcontrol can't show PX4FLOW video
Qgroundcontrol can’t show PX4FLOW video

Q:What is focus range PX4FLOW?
A:I did a test, the result is 0.4 – 0.8m.
( remark: document recommend to set the focus to 3m, I can do it by adjusting the lens of PX4FLOW )


Q:How to wiring to Pixhawk?
A:Connect PX4FLOW UART3 to Pixhawk’s serial port. Default id TELEM2


Finally I did a outdoor flight test, check here.


  1. Hello, Bellergy RC.
    I also wrote you a message in Google +
    I watched your video https://www.youtube.com/watch?v=pV8zmT8skPk. And it’s really cool!
    I tried to adjust PX4Flow with APM Copter 3.3.2 to keep the copter in a room on the spot without GPS. But nothing came of it. And you have all turned
    If you can adjust to pixhawk with PX4Flow for control coaxial quadrocopter (copter have small distance between the motors, only 20 centimeters), I’m ready to buy these customized PX4Flow and pixhawk.
    I wonder whether my suggestion to you?
    Thank you in advance

    1. Author

      Thanks for you like my video.
      Sorry, I’m not sure did I understood your question. Did you ask how to setup PXFLOW to work with coaxial copter?

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