ESC Calibration

Usually ESCs do not need calibration, in particular when the all digital DSHOT protocol is used. Only perform an ESC calibration if motors did not spool up smoothly during bench testing.
Ensure that the ESCs support calibration: some ESCs, such as the T-Motor Alpha, don't support calibration and they need specific setup for minimum and maximum PWM.

Wiring for ESC calibration

ESC calibration is typically done by sending the highest signal to the ESCs in the moment they are powered on, followed by the lowest signal. This method therefore requires that Skynode and the ESCs can be powered separately, as Skynode needs to be already running when the ESCs are powered on.

ESC calibration procedure

Warning: always remove propellers before starting an ESC calibration.
  1. 1.
    Connect the first power module to power input 1 (PWR1) of Skynode. Make sure the ESCs are not connected to the power module.
  2. 2.
    Provide power to the power input 1 through the power module. The ESC remain unpowered.
  3. 3.
    Connect AMC.
  4. 5.
    Navigate to Vehicle Setup - Parameters.
  5. 6.
    Set the parameter PWM_MAIN_DISARM to the minimum PWM value (usually 1000 us).
  6. 7.
    Navigate to Analyze - MAVLink Console.
  7. 8.
    Enter the following command: pwm test -p <max_pwm> -a -d <device> where:
    • <max_pwm> is the maximum PWM value (usually 2000 us).
    • <device> is the pwm device connected to the ESCs.
      • /dev/pwm_output1 if the ESCs are connected to the MAIN output.
      • /dev/pwm_output0 if the ESCs are connected to the AUX output.
  8. 9.
    Connect the ESCs to the power module.
  9. 10.
    Wait a couple of seconds, then cancel the command by pressing c and hitting enter.
  10. 11.
    Wait until the ESCs finished beeping.
  11. 12.
    Set the parameter PWM_MAIN_DISARM back to its previous value (usually 900 us).