Skip to main content
Home
The Baheyeldin Dynasty
The journey for wisdom starts with knowledge
  • Home
  • About
  • Site Map
  • Contact

Enhanced OnStep Calculations Spreadsheet

  1. Home

By Khalid on 2021/12/30 - 20:39, last updated 2021/12/31 - 18:49

OnStep is a full featured telescope controller firmware that was created and maintained by Howard Dutton.

As of late 2021, it runs on several types of boards with a variety of microcontrollers, including the Teensy, ST's STM32F103, STM32F303, STM32F446 and Esspressif's ESP32.

In order to convert a mount to OnStep, one needs to fill out a spreadsheet created by Howard that accounts for various parameters, such as one or two stages of gear reduction, microstepping, an motor shaft RPM.

The results from these calculations impact the mechanics of the mount (e.g. pulley sizes), speed of slewing, tracking resolution and accuracy.

Due to recurring confusion on the OnStep group with interpretation of the spreadsheet, some enhancements were added to better flag when unworkable or borderline situations arise with configuration settings.

The spreadsheet linked to below is an enhanced version that uses the exact same calculation as Howard's, but provides the user feedback when certain parameters are out of range.

Specifically, these enhancements are:

  • Spells out a lower as well as an upper range of steps per degree (12,800 to 62,100). These are mainly for imaging, which is most OnStep users. Lower values can be used for visual observing). OnStep has been tested with up to 102,000 steps per degree, but Howard still recommends staying under 62,100.
  • Lists the three recommended microstepping values (1/16, 1/32, and 1/64). Some users conflate physical gear reduction with microstepping. Too much microstepping (e.g. 1/128, 1/256) will negatively impact stepping accuracy and torque. Too little microstepping (full step, 1/2, and 1/4 microsteps) will increase the chances of resonance and stalling. The recommended three microstepping values offer a reasonable compromise and work for the vast majority of mounts.
  • Warns if the motor shaft is too fast for most stepper motors when slewing. What this does not take into account is the use of MICROSTEPS_GOTO, which allows faster slewing speeds without increasing the RPM of the motors. Hopefully, a future update will add this.

By catching these common mistakes as early in the conversion process as possible, we are avoiding a common situation where users go to the OnStep group for help, only to realize too late that they miscalculated something. For example, they need different sized pulleys, and they buy them from eBay with many weeks of shipping.

So we hope that this results in less user frustration, and reduced volume of support questions on the group.

Download the OnStep Enhanced Spreadsheet, do the what-if analysis on it, then head over to the Online Configuration Generator to easily create a Config.h file for your setup.

Contents: 
Astronomy
Tags: 
OnStep
  • Add comment

Comments

Doug (not verified)

OneStep capabilities

Mon, 2022/04/11 - 10:06

Hi there from Waterdown!
If this isn't the correct place to ask, please delete.
I'm looking at getting my niece something for her interest in Astronomy.
Has the OneStep or similar been developed to move a calibrated scope to a specific position ie Horse head Nebulea? I'm hoping to cobble a Meade ETX together with a "GoTo" type mount. Any advice?
Thanks
Doug

  • reply

Khalid

It is a Goto system

Mon, 2022/04/11 - 12:26

Yes, OnStep is a goto system. So it can be pointed to objects.
And if you get the Smart Hand Controller (SHC), it will have a comprehensive catalog of objects.

However, the ETX may not be a viable platform for it.
To use OnStep, you have to use stepper motors though, and that is the main challenge. I don't know anyone who tried to fit stepper motors into an ETX.

Also note that the Horsehead Nebula will not be visible to the human eye. It only appears in sensors modified to sense Hydrogen Alpha emission.
The ETX is usually very slow optically speaking (i.e. F/ratio), so it would not be usable with cameras.

So there are mechanical and optical obstacles to convert an ETX to OnStep.

  • reply

Current

Pandemic

  • COVID-19
  • Coronavirus

Search

Site map

Contents

  • Family
    • Khalid
    • Ancestry
    • Extended
  • Friends
  • Nokat نكت
  • Writings
    • Cooking
    • Culture
    • Science
    • History
    • Linguistics
    • Media
    • Literature
    • Politics
    • Humor
    • Terrorism
    • Business
    • Philosophy
    • Religion
    • Children
  • Technology
    • Linux
    • Arabization
    • Drupal
      • Association
    • Software
    • Internet
    • Technology in Society
    • Digital Archeology
    • NCR History
    • MidEast Internet
    • Programming
    • Saudi ISPs
    • Miscellaneous
  • Places
    • Canada
      • Weather
    • Egypt
      • Cuisine
      • Alexandria
      • E.G.C.
    • USA
    • Saudi Arabia
  • Interests
    • Astronomy
    • Fishing
    • Photography
    • Snorkeling
    • Nature
    • Photomicroscopy
  • Miscellany

In Depth

  • al-Hakim bi Amr Allah: Fatimid Caliph of Egypt الحاكم بأمر الله
  • Alexandria, Egypt
  • Arabic on the Internet
  • Articles on the history of Muslims and Arabs in the Iberian Peninsula تاريخ المسلمين و العرب في الأند
  • DIY GOTO Telescope Controller With Autoguiding and Periodic Error Correction
  • E.G.C. English Girls College in Alexandria, Egypt
  • Egyptian Cuisine, Food and Recipes مأكولات مصرية
  • George Saliba: Seeking the Origins of Modern Science?
  • Internet Scams and Fraud
  • Mistaken for an Arab or Muslim: Absurdities of being a victim in the War on Terror
  • Mistaken Identity: How some people confuse my site for others
  • One People's Terrorist Is Another People's Freedom Fighter
  • Overview of Google's Technologies
  • Photomicroscopy
  • Pseudoscience: Lots of it around ...
  • Resources for using Google Adsense with Drupal
  • Rockwood Conservation Area, Southern Ontario
  • Selected Symbolic Novels And Movies
  • Snorkeling the Red Sea near Jeddah
  • Updates and Thoughts on the Egyptian Revolution of 2011

Recent Content

Most recent articles on the site.

  • Origin Of COVID-19: Natural Spillover, Lab Leak Or Biological Weapon?
  • Kamal Salibi and the "Israel from Yemen" theory
  • How To Upgrade HomeAssistant Core In A Python Venv Using uv
  • Ancestry - Paternal Side
  • Review of Wait Water Saver For Whole House Humidifiers
more

Most Comments

Most commented on articles ...

  • Another scam via Craigslist: offering more than asking price
  • Warning to female tourists thinking of marrying Egyptians
  • Craigslist classified for used car: Cheque fraud scam
  • Winning the lottery scam email: World Cup South African lottery
  • Email Scam: BMW 5 Series car and lottery winning
more

About Khalid

Various little bits of information ...

  • Khalid Baheyeldin: brief biography
  • Presentations and Talks
  • Youtube Videos
  • GitHub Projects
  • Drupal.org Profile
  • Astrophotography @ Flickr

Sponsored Links

Your Link Ad Here

Tags

Android Mobile Ubuntu Sony OnStep OpenWRT Router Ericsson COVID-19 Rogers Coronavirus Arabic Kubuntu Home Assistant GSM Telescope tablet Spectrum Scam Python 419 Laptop Firefox DIY CPU Conspiracy Comet Balkanization backup App
More

© Copyright 1999-2025 The Baheyeldin Dynasty. All rights reserved.
You can use our content under the Terms of Use.
Please read our privacy policy before you post any information on this site.
All posted articles and comments are copyright by their owner, and reflect their own views and opinions, which may not necessarily be consistent with the views and opinions of the owners of The Baheyeldin Dynasty.

Web site developed by 2bits.com Inc.