My OnStep Kicad Project

Building OnStep with Kicad (with all necessary footprints and 3d image files).

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Project based on the OnStep Telescope Controller (and Smart Hand Controller), with minor alterations to the originals (basically slightly different modules and board layouts), built with KiCad.

OnStep is an open-source (hardware & software) Telescope Mount Goto Controller. The main board can be build using a variety of microprocessor including ESP32, STM32 (Blue/Black Pill) and even the humble Arduino Mega plus others. I will include the necessary files to build the project using Kicad.

OnStep is unusual in that it uses virtually no discrete components, it relies on existing low cost modules available on ebay. The modules are soldered onto a dedicated PCB, making the project ideal for those new to electronic or lazy like me (a lot less soldering and effort is required).  The original designs were created with EasyEDA Designer, but as I prefer to work with KiCad and local filess, I created this project.

My version of the Smart Hand Controller can be found here: ( Note, my version uses the ESP32 Dev Kit 1 module (as I had a few in stock), mounted vertically on the underside of the PCB. This allow for a considerably slimmer profile for the enclosure. In addition, I only populate the main RJ12 for communication with the main controller as the second RJ12 connector (SR4) is just an auxiliary port.

I will include all schematics, footprints, symbols and 3d images for the project.


OnStep with STMF303

Portable Network Graphics (PNG) - 317.79 kB - 10/28/2020 at 01:11


Portable Network Graphics (PNG) - 80.27 kB - 10/16/2020 at 09:36


Portable Network Graphics (PNG) - 94.82 kB - 10/16/2020 at 09:36


Portable Network Graphics (PNG) - 280.54 kB - 10/15/2020 at 14:58


Portable Network Graphics (PNG) - 340.20 kB - 10/15/2020 at 14:58


View all 8 files

  • 1 × STM32F103C8T6 Microprocessors, Microcontrollers, DSPs / ARM, RISC-Based Microcontrollers
  • 1 × RTC Module RTC Module
  • 1 × ESP8266 WeMos D1 Mini
  • 1 × CP2102 CP2102 Module
  • 3 × TMC2209 or similar motor controller

View all 7 components

  • Version using ESP32VROOM

    Michael O'Toole08/29/2020 at 12:37 0 comments

    I need a version of the hand controller that can be reduced in size so I added an optional build using ESP32VROOM as it's probably the smallest board with all the necessary IO's. If I can get it small enough, I might reuse my faulty Meade Autostar 497 case...

  • Versions

    Michael O'Toole08/24/2020 at 19:32 0 comments

    I have two version of the OnStep Smart Hand Controller PCB, the first version contains a single RJ12 connector for the basic functionality. The second PCB includes the extra RJ12 to allow addition ST4 functionality.

    The first version's PCB and matching enclosure, have tested and turned out perfect pretty decent. The second version, while complete, has not been tested and the second enclosure has not been completed yet..

    I intend to include an enclosure for the original hand controller PCB and will try to reduce the profile as much as possible just as soon as I get some free time...

View all 2 project logs

  • 1
    OnStep Hand Controller (my version of the board)

    As there are only a few components and a single module build instructions are probably not required, simply match to available images.

    The ESP32 module mounts on the underside. The caps and resistor networks have silkscreen on top but should also be mounted on the underside (making sure polarity is correct for capacitors), this allows us to reduce the profile of the enclosure.

  • 2

    Pin 1 of the OLED is Ground, pin 2 is VCC, so make sure you get an OLED with this pinout (versions with pin 2 Ground and pin 1  VCC are also available so be careful. The OLED mounts on top, keep the pins short as possible, trim if possible...

    The second RJ12 connector (ST4) is not used in my version, the board supports it but we will need to modify the current 3D enclosure to allow for the second RJ12 connector... perhaps later when I have time...

    There should be no need to remove the PCB to reprogram it, simply plug in the micro USB cable in the top.

View all instructions

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