The handpad input

The Seletek has a dedicated handpad connector that accepts simple momentary push-button switches. No electronics are needed — the connector provides the logic levels, and a button press grounds the input, signalling the direction of movement. Speed can be selected by holding one button alone (slow) or both together (fast), depending on the software version's handpad configuration.

Building the handpad

Simple two-button handpad for Seletek focuser control — front view
A simple handpad — two momentary push-buttons in a small enclosure, connected to the Seletek via a thin cable.
Simple two-button handpad for Seletek — inside wiring
Inside the handpad enclosure — two switches and a thin four-conductor cable to the Seletek handpad port.

Components needed:

  • Two momentary push-button switches (normally open, any size)
  • A small project box or enclosure
  • Four-conductor cable, length to suit your setup (2–5 m is typical)
  • A connector matching the Seletek handpad port (check the Seletek manual for the exact connector type)

Wiring:

  1. Run the cable from the Seletek handpad port to the handpad enclosure.
  2. Connect one switch between the IN1 and GND lines — this is the "focus in" direction.
  3. Connect the other switch between the IN2 and GND lines — this is the "focus out" direction.
  4. Leave the +V line connected if your handpad will eventually add an LED indicator; for a basic two-button unit it is not needed.

Using the handpad

Press and hold the IN/OUT button to move the focuser continuously. Release to stop. Most Seletek software versions also allow pressing both buttons simultaneously to select a different speed — consult the software's handpad settings panel to configure the fast/slow threshold and speed multiplier.

Works alongside ASCOM: The handpad input works independently of the ASCOM driver connection. You can move the focuser with the handpad even while the automation software is connected — the Seletek tracks the position either way.