OnStep ESP32 Smart Hand Controller SHC

In December 2018, Dave Schwartz completed a design for a Smart Hand Controller (SHC) for the OnStep open source telescope controller.

After completing the hardware, I ported the firmware for it, from the Teensy 3.x to the lower cost ESP32.

Here is a video that I did demonstrating the features.


And ESP32 SHC can now be flashed with the updated SHC firmware and configured for WiFi. Up to three mounts can be configured in the Config.h and Extended.config.h.

In Config.h you need:


And in Extended.config.h


You also need to define your SSID, password and IP address in that file.

Here is a video showing the wSHC in action.

Functionality of the SHC

The general functionality of the SHC is described on OnStep's SHC User's Manual.


Here is an image of the SHC PCB, V1.03.

You can order the PCB by itself from this EasyEDA project.

Roman Hujer's modified PCB uses normal axial resistors instead of the resistor network, which sometimes are difficult to source.

There is also a variant by Martin Laza without a PCB at all, and is more compact. The design also includes a custom SHC 3D printed case.

Ken Hunter created his own PCB with a different layout, in order to fit it in an off the shelf Hammond 1591XXB plastic case.

Infrastructure Kit

And here are the infrastructure components that form the kit.

You can find a Bill Of Material (BOM) with detailed description of each item, on the above link for the EasyEDA project. In addition to the BOM items, you can also use this 5-way 10x10x10mm Multi-Direction Switch from AliExpress or eBay to use as a joystick.

Assembly Instructions for the ESP32 SHC

The OnStep Wiki Files section has the detailed assembly instructions.

The document also contains pictures of the parts that you can order at eBay or other online market places.

3D Printed Case

The instructions to obtain the STL files necessary to print your own 3D Printed case, are available in the above assembly instructions. The instructions also cover how to print the parts needed.

Ordering An ESP32 SHC Kit

The ESP32 SHC can currently be ordered from the following sources:

  • 1 X ESP32 SHC available for sale. Contact Khalid for more details.
  • Otherwise, contact Ken Hunter who sells pre-assembled SHCs with a 9-foot coiled ST4 cable. You will have to flash it with your specific WiFi settings when you receive it.


In addition to the hardware PCBs mentioned previously, here are the contributors to the firmware and catalogs.

  • The SHC firmware was originally written by Charles Lemaire for TeenAstro, which is a derivative of OnStep but only for the Teensy.
  • Dave Schwartz created the ESP32 SHC PCB.
  • Khalid Baheyeldin ported the firmware to the ESP32, and expanded the catalogs with much more objects, and far more precise coordinates.
  • Howard Dutton refined the firmware immensely.
  • Jesco Topp contributed the WiFi feature, to make the ESP32 SHC completely untethered.



SHC with nodeMCU esp8266

Hi, very nice project... is it possible to realize it with an nodeMCU esp8266 processor instead of an ESP32?? or teansy 3.2? i can't find a pcb with...


No. The SHC code and the PCB work only on the ESP32.