OnStep

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.

For those of us who do astronomy, whether visually or for astrophotography, polar alignment is a procedure that we are familiar with, and have to do before every observing sessions, unless we have a permanent observatory.

Today, I released my OnStep Python API on Github. This API allows commands to be issued from any Python 3.x program to an OnStep controlled telescope.

This allows a lot of use cases, for example, testing certain scenarios, or automating certain tasks.

Several examples are provided as starting points on how to write your own programs.

Patches for features, and fixes are welcome.

Yesterday, I released ETL-Astro, a set of Python programs that generate astronomical catalogs in a variety of formats from license friendly data source, allowing for incorporation in GPL-licensed products.

The programs can do the following:

This is a short video demonstrating how to use a Hall Effect sensor and a magnet to implement Periodic Error Correction (PEC).

Here is an example on eBay for a standalone 3144 Hall Effect Sensor. And here are the small neodymium magnets.

After nine months of modifying the OnStep open source telescope controller to run on the cheap STM32 ARM Cortex M3 microcontroller, it is time to reap the fruits of this long labour: I have an OnStep powered mount ...

Over the winter, I worked with Howard Dutton, the author of OnStep Telescope Controller, to make it work with the low cost STM32 ARM Cortex M3 microcontrollers. This involved writing a hardware abstraction layer (HAL), so adding different architectures in the future would not be too hard, as it was.

One of the obstacles in using OnStep is the process of configuring it. A user should start with a spreadsheet that calculates certain parameters. The user is supposed to check that they lie between acceptable ranges mentioned in the spreadsheet.