OnStep is a computerized telescope goto controller designed by Howard Dutton (Stellarjourney.com) and allow to use on a variety of mounts.

It supports Equatorial Mounts (GEM, Fork, etc.) as well as Alt-Az mounts (like Dobsonians and similar) and Tangent Arm mounts.

OnStep is compatible with the LX200 protocol, so it can be controlled from other planetarium software like SkySafari, CdC (also without ASCOM), Stellarium, etc.

Instein.eu has designed its own OnStep hardware based on little modifications of original code for ESP32 boards to allocate the most relevant features on a convenient case size and support Instein motor kits for each mount, therefore, custommers can modify the source code to their owns or adquire an OnStep Custom Drive for their project.


OnStep supports a variety of conection options:

  • Micro USB serial port based on CP2102 chip.
  • Bluetooth serial port class 4.2 BR/EDR BLE.
  • WiFi 802.11 b/g/n command channel with built-in website accesible throught any webbrowser. (Configurable as Access Point or Station)
  • ST4/Hand Control port: OnStep HC is optional, it can be plugged here and bypass the ST4 funtions to the HC ST4 port.
  • AUX port: For conecting any serial TTL com device; aditional wifi/bluetooth/USB, ethernet to serial,  serial RF Link, etc.
  • ASCOM Driver with IP and Serial support
  • Free Android App with a large object catalog database useable over WiFi or Bluetooth
  • Full planetarium software that controlls all features: Skyplanetarium
  • INDI Drivers to use from Linux with CdC, KStars, Asiair or Ekos


All questions related to instein products should be posted by contact to Instein.eu, therefore, you can learn more about OnStep features on the OnStep Group.

OnStep is open source free software, licensed under the GPL: License.txt

Losmandy OnStep G11-GM8- G9-AZ8-HGM200 GoTo Kit - Gemini2 Retro-Fit Kit Alternative

Losmandy OnStep G11-GM8- G9-AZ8-HGM200 GoTo Kit - Gemini2 Retro-Fit Kit Alternative

OnStep retrofit kit for Losmandy G11, GM8, G9, AZ8, HGM200 and their Celestron equivalent non GoTo m..


OnStep Hand Control

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To be updated soon.New stock availavility expected on October 2020..


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OnStep Custom Drive

With TMC5160 Stepper drivers installed, shipped with custom configuration for user stepper motors an..


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