Celestron focus motor

Warning: The DC-IN jack (if fitted) should NEVER be used when the HBG3 is connected to any mount via the AUX cable.

Options:

1. AUX from HBG3 to mount, AUX from mount to focuser recommended
2. AUX from HBG3 to focuser, 12v DC feed to HBG3 (jack to pads RAW and GND)

The HBG3 with Nunchuck can also be directly connected to a Celestron Focus Motor in standalone mode, when used with a non-Celestron mount. In this scenario one could power the HBG3 with 5V into its USB port. Or one might instead feed 12V into the HBG3 using its GND and RAW pads and the HBG3 will then pass that 12V through the AUX cable to also power the Focus Motor, simplifying the overall wiring at the mount.

• Pressing and holding both Nunchuck buttons simultaneously for 2 seconds will toggle between the slew+focus mode and a special focus-only mode with "Focus presets" using the buttons
• Holding the "C" button while in slew+focus mode selects the focuser.
• Holding in the "Z" button selects faster speeds while slewing
• Up/Down for coarse focus
• Left/Right for fine very focus

The Nunchuck has two modes of operation: Push-and-hold both buttons for a couple of seconds (BLUE LED will flash) to change between modes 1,2. The current mode is saved in NVRAM and survives resets and power-cycles.

Slew+Focus mode: The thumbstick slews the mount by default. Holding in the Z button while slewing gives a higher speed range. Holding in the C button instead moves the Focus Motor, if present. Focus-only mode: The thumbstick moves the Focus Motor. The buttons are used to remember and return to "preset" or "saved" focus positions. Push-and-hold a single button to memorize the current focus position (BLUE LED will flash). Later, tap that button to cause the Focus Motor to return to the saved position. Presets are saved in NVRAM, so they survive resets and power-cycles. Whenever the thumbstick is controlling the Focus Motor, the Up/Down axis gives a higher variable speed range than the Left-Right axis.

A stepper motor can be wired to the HBG3 through a motor driver module. It will then act the same as a Celestron-branded Focus Motor with full control from the hand-controller, CPWI, and SkyPortal/SkySafari apps. This is described more in this post on CloudyNights