Open Source Telescope Controller Puts Smart Features In Old Telescopes

In times like these, we all need to look beyond ourselves. This project might help: OnStep is an open-source telescope controller, a device that controls a telescope to point at something interesting in the sky. Want to take a look at M31? Use an app on a PC or smartphone, select the object and the OnStep will pan and tilt your telescope until the Andromeda Galaxy pops into view.

Smart telescopes are not new: we’ve seen telescopes like the Meade LX90 that include smart controllers that can, with varying degrees of success, use GPS signals to figure out the time, the location and which way to point to see Uranus. These use proprietary controllers, though, and are generally expensive. OnStep is designed to be simple, low cost and buildable from off the shelf parts.

It is pretty hardware agnostic: the controller can be an Arduino, a Teensy 3 or even an ESP32. The PCB design can work with any of these controllers. The same is true of the motors that move the telescope, so you can build the device from parts that you might have lying around. Many of those who have built OnStep controllers have adapted older telescope mounts that are motorized but aren’t smart. Others have used older mounts and replaced the slow, inaccurate motors with more precise ones that make the telescope more accurate and smooth. The gallery of telescope builds on the OnStep wiki is a great place to start and see examples like this 30-year old Celestron telescope that was brought into the 21st century with a OnStep conversion, or this conversion of a 1960s telescope that adds a smart mount.

It’s a great looking project that has the basics mostly sorted, but which is still being worked on and improved by a dedicated group of users. While we tend to focus on ourselves in difficult times, sometimes it is better to look up in the sky and see that the stars are still shining.

10 thoughts on “Open Source Telescope Controller Puts Smart Features In Old Telescopes

  1. Oooooo will have to bookmark this. Got a Celestron that’s been sitting unused since one of the lounge lions chewed up the controller. (Which I could probably patch up, just seems it’s been bottom of the priority list.)

  2. This is a great article, but missing a few small points, e.g., the person behind this superb creation, and the fact that the OnStep has been used on all manner and all ages of telescope mounts–equatorial, traditional alt-azimuth, and Dobsonian.

    BUT… no problem ; just start at the hyperlink given in the article, “gallery of telescope builds on the OnStep wiki” , and then check out the following (and you can always type “OnStep telescope controller” into your favorite searchmotor. Who’d ‘a thought, right?).

    OnStep: A Full Featured Open Telescope Controller
    Submitted by Khalid on Sun, 2017/10/08 – 20:32

    “OnStep Telescope is an open, very capable and feature rich telescope controller by Howard Dutton….
    “This page was created because it was very difficult for me to find information about OnStep. The main venue for exchanging information on it used to be a closed Yahoo…
    “OnStep Telescope Controller STM32 PCB and ESP32 SHC Kits”
    Submitted by Khalid on Mon, 2018/09/10 – 17:30

    “A while back, I completed a port of the open source OnStep Telescope Controller firmware to the STM32 Blue Pill ARM Cortex M3 32-bit MCU. Later…”
    Cloudy Nights LLC
    “OnStep telescope controller for SkyWatcher EQ5”
    “Control Your Telescope Using Stellarium & Arduino”
    By NelsonFerraz in WorkshopScience
    Plainfield Astronomy
    “OnStep Electronics”

    “OnStep is a project created by Howard Sutton. His project called out a set of hardware modules…”

    1. Some of this is looking a bit familiar. Was it based on earlier “universal” stepper control projects that used maybe a PIC or an 8051 late 90s early 2000s???

      It was all hosted, forum and all on some ISP webspace, (which practically all went away over the years.) Last I tried to get up to speed on it, the whole forum was consumed in a flame war about best way to partial step and the superiority of various drivers. You know, the kind of impossible time to be a n00b somewhere because all factions accuse you of being a sock puppet for one of the others.

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