Before moving on, the ESCs (electronic speed controllers) will need to be calibrated. This process tells the ESCs the minimum and maximum throttle range sent from the flight controller to the ESCs. If this is not done before flight, your motors may not respond correctly – causing unstable or unpredictable flight.
This calibration process is done using the Throttle Calibration button and by disconnecting and reconnecting your flight battery in a specific manner: you will need to have a charged battery and be able to connect and disconnect it during this process. Again, make sure that your propellers have been removed.
The Parallax GroundStation application will visually indicate when to unplug or plug in your battery during this calibration process. Watch for screen indicators.
To hear what the series of beeps in instructions 4 and 5 should sound like during a successful calibration, download this .zip file containing a wav sound file for each instruction [1].
Links
[1] https://learn.parallax.com/sites/default/files/content/ELEV-8/v3-Assembly/Step25-ThrottleCalibrationBeeps.zip