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This guide covers stroker motion state, calibration bounds, hall reference positions, and software-enforced motion settings for the Melody hardware device, controlled over WiFi using the single production API:
https://api.getmelody.io
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Authorization: Bearer <YOUR_JWT_TOKEN>
Content-Type: application/json

Stroker Status (Read)

Dynamic positional and velocity state of the linear haptic actuator (“Stroker”).
FieldTypeDescription
currentPositionAnglefloatCurrent stroker position (radians)
currentPositionRangedint32Current position (0–10000 points)
targetPositionAnglefloatCurrent motion target position (radians)
targetPositionRangedint32Target position (0–10000 points)
currentVelocityAnglefloatCurrent velocity (radians/second)
currentVelocityRangedint32Current velocity (points/s)

Stroker Calibration Info (Read)

Hardware-derived physical motion boundaries captured during calibration.
FieldTypeDescription
calibrationLowPositionfloatLowest physically blocked position (mm)
calibrationHighPositionfloatHighest physically blocked position (mm)
calibrationLengthfloatTotal stroke length detected during calibration (mm)
hallSensorLowPositionfloatHall sensor reading at low calibration limit (mm)
hallSensorHighPositionfloatHall sensor reading at high calibration limit (mm)
calibrationShiftfloatFirmware constant offset applied post calibration (mm)

Stroker Settings (Read/Write)

Software limits and motion preferences that operate inside calibration bounds.
FieldTypeDescription
lowPositionShiftfloatUser offset from calibrated low limit (mm)
highPositionShiftfloatUser offset from calibrated high limit (mm)
maxVelocityfloatMax velocity limit set by user
playbackRatefloatPlayback speed multiplier (1.0 = normal speed)

Best Practices

  • Only adjust Position Shift and Velocity limits after a successful calibration
  • Keep user motion bounds inside hardware-detected calibration limits
  • Apply velocity caps when streaming (HPS) or looping (HLC) to ensure smooth, safe motion
  • All position shifts are in millimeters (mm) relative to calibration bounds

Next, explore how to read stroker status, update motion settings, or control loops & timelines in the API Reference → Stroker WiFi tabs.