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The Smart Hand Controller (SHC)

This OnStep add-on is a hand controller with display which can be used to set up and control OnStep.  It's an adaptation (and extension in some respects) of Charles Lemaire's excellent "Teen Astro" hand controller firmware that allows it's use with a stock OnStep system.  Nearly all features are supported so an SHC+OnStep is a stand-alone telescope controller capable of setup, alignment, and operation (gotos to stars, Messier/Herschel400 objects, the planets, etc.)

There are currently two versions of the SHC: one based on the Teensy 3.2 and the other on the ESP32.

The Teensy-based SHC is a wired-only device that plugs into any OnStep controller that has an ST4 port*. The ESP32-based SHC can now be used as a wired or wireless device because the ESP32 has built-in WiFi hardware which is now supported by versions of the software in the standalone code repository as of version 3 and higher. For options to power the wireless SHC (wSHC), see the 'Power' section at the end.

*** NOTE: if the SHC is plugged into OnStep's ST4 port NO OTHER DEVICES may be connected to the port (using a 1 port to 2 port modular adapter for instance) at the same time. ***

*** NOTE: during firmware upload to the SHC you must use the Teensy3.2 micro-usb connection but you must never have the SHC connected to other hardware (OnStep) via the ST4 connection (or Serial3/etc.) at the same time. ***

*** NOTE: versions of the
EasyPCB SHC prior to 1.10 may have incorrectly positioned and/or labeled VCC and Gnd pins on the display connector.  Examine the pcb to be sure those match up with your display.  ***

The Teensy 3.2 SHC PCB and Case

*** Its up to you to understand the design, connection, limitations, and use of this device and it's components, I accept no responsibility. ***

My EasyEDA PCB and 3D printable case for this makes for an easy to build controller.  I can finish one of these in a single evening including printing the case, all soldering, and assembly.  Some SMT soldering is required but that's been pretty easy in my experience (just be careful to position each button properly while soldering it's first contact.)  The exact display I used was this 1.3" white OLED (SH1106.)  Other parts used are shown in the EasyEDA BOM.  There are two button types listed one has a round post and the other square.  I used the round ones and my 3D printable caps (which I made from glow in the dark filament) fit these.  For the square post type push buttons these caps should work I think (they are the same as used for the Basic Hand Controller and see that device for more info.)  If you don't have the 3D printer you'll have to find a case of similar size and cut/drill to make the PCB fit (which I imagine will not be a trivial task!)


SHC Case design and STL files

Assembly notes:

  • Be sure the display connections match up with the SHC PCB and Schematic, the order of pins can vary depending on display manufacturer.  The PCB is designed for a pin order of Gnd, Vcc, SCL, and SDA.
  • The SHC PCB's provision for a 6P6C RJ12 jack (for ST4 interface pass-through) isn't supported yet and the part must also be omitted if using my 3D printable case design.
  • All components are soldered directly to the PCB (no socket headers.) 
  • Be careful to install the resistor packs, RP1 and RP2, in their correct orientation with pin 1 having a small box on the PCB silk-screen.  Pin 1 on the device has a small dot next to it.
  • The Teensy3.2 has pin headers soldered on and then gets soldered to the back of the PCB first.  I then cut off the excess pin length extending through the PCB front side with small diagonal cutters.