RPM – Setup

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  • RPM (Revolutions Per Minute)

Motor Details

  • Determine the number of magnetic poles (blades in OpenTX)
    • Emax MT1806-2280KV
    • Framework 12N14P
    • 14P = 14 Magnets = 7 Pole Pairs = 7 blades in OpenTX
  • Note the KV 2280 revolutions per minute per volt


  1. Connection diagram
  2. Turn On Tx
  3. Power up Rx with sensor connected
    Motor connected with propeller removed
    Throttle at minimum
  4. Observe the LED that flashes on the sensor
    Only LED 0 should flash, if not see “Sensor Pole Pair Setting” below
  5. Press MENU
  6. Long press PAGE twice
  7. Scroll down to “Discover new sensors”, press ENT
  8. New sensors will be discovered, with “Stop discovery” selected press ENT

  9. Scroll up and select the “RPM” sensor

  10. Long press ENT

  11. Select “Edit”, press ENT

  12. Scroll down and select Blades

  13. Press ENT
    Scroll to select the number 7
    7 magnet pairs = 14 magnets = 14P

  14. Press EXIT twice

  15. Press EXIT


  1. With propeller removed increase the throttle
    Observe RPM values change
  2. Increase throttle to maximum
    Note the RPM 25,011rpm

  3. If A2 is present and connected note the battery voltage A2 11.3V
    If A2 is not present or not connected use a voltmeter attached to the battery
    Often A2 is present but is not connected in which case the voltage displayed is an arbitrary value. Don’t use this value.
  4. Multiply the KV with battery voltage
    2280 x 11.3 = 25,764 rpm (theoretical)
  5. The theoretical RPM (25,764) should be close to the sensor RPM (25,011)
    In this example there is a 5% difference
  6. Use a tachometer to verify the measured RPM
    DANIU DT2234C+

Sensor Pole Pair Setting

  1. Power on the sensor
    Observe the number of the LED that flashes
    LED 0 should be the only one that flashes

    If a different LED flashes, or more than one LED flashes set the sensor by pressing the Key button
    Example of incorrect LED flashing
  2. Press the Key button till an LED turns on

  3. Repeatedly press the Key button till only LED 0 is lit
  4. When only LED 0 is lit turn the sensor off and then on
    Only LED 0 will be lit