Python API for the OnStep Telescope Controller

This API interfaces to OnStep, allowing scripting of test scenarios, actual telescope motion, ...etc..

Works over the following devices:

• USB serial
• WiFi (requires OnStep's Smart Web Server)

This modules requires Python 3.x, and was tested with 3.8.10. You also need either or both of:

• Python Serial if using USB serial.
• Python Socket if using WiFi.

Although this is written specifically for OnStep, it is mostly compatible with other telescope controllers that use the LX200 Command Protocol.

Before using this API, you need to edit the examples/config.py. A few required changes are needed in the examples/config.py:

a. How to connect to your controller? This can be over WiFi, or a serial USB port. Note that for FYSETC S6 the port is /dev/ttyACM0, and for the Blue Pill and ESP32 controllers, the device name is /dev/ttyUSB0 b. The latitude and longitude (lat and lon) c. The UTC offset (utc)

If you plan to use the WiFi instead of a serial USB cable, you need to change the HOST parameter in the config.py file.

This method will present a menu for most of the example programs:

cd onstepy
./examples/menu.py

The following sample programs are provided. Adapt them to your own needs:

• init.py - Sets coordinates, date, time, UTC offset, and starts tracking
• align.py - This starts a 1-Star Alignment procedure (select the star's RA/DEC in config.py)
• home.py - Return home
• slew.py - Slew to a star
• slew_altaz.py - Slew to an Alt/Az position
• drift_test.py - Test if there is drift in RA (equatorial) and RA/DEC (Alt-Az)
• batch_align.py - Upload alignment points, with actual vs. instrument coordinates, and let OnStep do an alignment calculation
• stress-test.py - Repeatedly do slews west and east of the meridian, then wait for tracking then repeat. Useful to test thermal shutdown, mount accuracy ...etc.
• polar_align.py - Do a polar alignment using the :MP method (now present in the Android app)
• backlash.py - Adjust the backlash on a terrestrial object
• report.py - Report on an ongoing test

Khalid Baheyeldin