Saturday, March 14, 2020

OpenTx Settings for DSM-X receivers

Mixer Screen

Ch1, Ch2, Ch3, Ch4: (THR, AIL, ELE, RUD): Normal default mixes, but different order than FrSky default.  Be sure you're set the input properly for each channel.
Ch5: AS3X/SAFE:  Set to any 3-position switch you like.
Ch6: Emergency: Bind to momentary switch.  SAFE Panic Button when switch is pulled.

Outputs Screen

  • All Channels: Set limits, Min=-80.0, Max=80.0.
    This compensates for fact that OpenTx 100% = Spektrum 80%.
  • Ch2, Ch4 (AIL, RUD): Set Direction=INV to reverse  inputs.


Set throttle range by usual procedure:  Power on radio, throttle stick max, power on plane, after beep lower throttle stick to min.


Tech note:
https://www.spektrumrc.com/ProdInfo/Files/Remote%20Receiver%20Interfacing%20Rev%20A.pdf

At ±100% travel, the data range is equivalent to a “Servo Position” data range of approximately 341 to 1707 which translated to PWM equals 1102µs to 1898 µs.