The system fits on all EQ-5 mounts; SW EQ5, Celestron CG-5, Bresser Exos II

Based on Nema 17 stepper motor positioning system, this kit includes all necesary to fully control your mount, hand controller is optional but not needed, package content:

  • 2x Nema17 0,9º Step Angle Stepper Motors (5,4VDC, 0,9A, 36Ncm nominal Specs), installed on brackets.
  • 2x 16 teeth and 2x 40 teeth pulleys, 2x belts
  • 2x Flat RJ45 cables 1 metter long.
  • Main Drive with TMC5160 stepper motor drivers installed, 2x antenna for BT and WiFi.
  • 2x reusable nylon fasteners, system mounting screws.


  • Permanent PEC
  • Up to 6 star goto asisted polar aligment correction.
  • Automatic refraction rate compensation.
  • Custom park and home positions.
  • Integrated Bluetooth and WiFi server/command channel.
  • Refraction rate compensation
  • Automatic meridian flip, meridian flip pause at home.
  • Custom backslash setting.
  • Up to 600x slew rate.
  • Custom limits (overhead, horizon, meridian)
  • Custom observing sites.
  • Large object database: Solar System, Messier, NGC/IC, Herschel, Bright Stars, User Custom Catalog.
  • Manual speed/guide speed rates: 0,5x, 1x, 2x, 8x, 24x, 48x, 300x
  • Slew Rate: Adjustable 150 to 600x
  • Tracking: Sidereal, Lunar, Solar, Fine Adjust
  • Power source: 2A 12VDC (up to 400x) for 600x slew rate use 18VDC (recomended). Max 24VDC. 
  • Tracking resolution, in arc-sec:  0,035
  • Guide resolution, in arc-sec:  0,56 


Installation is as easy as this example for Bresser Exos II, other EQ5 mounts are similar, they share the same motor hardware design;


Compiled firmwares, source code and manual to be updated soon.

Defaul Device name for BT and WiFi are "OnStep"

Default WiFi key is "password", default IP is: (port 9999 for command channel and android app), for web browser conection just type: in your web  browser address tab. Wifi SSID and key can be changed, BT device can not. In case of wifi key lost you can restore defaults by uploading again wifi firmware part.

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EQ5 - Bresser Exos II OnStep Goto Kit

  • Brands Instein Astro
  • Product Code:EQ5 GoTo Kit
  • Availability:In Stock
  • 360.00€