python-zwoasi

Python wrapper for the ZWO ASI v2 camera SDK, enabling control and image capture from ZWO USB cameras. This version includes a much more user-friendly wrapper, and improved documentation across the board.

For a version of the manufacturer's repo with ONLY improved documentation (no updated functionality), refer to the branch titled "Improved-documentation-only".

User-friendly vs original syntax

This fork adds convenience methods so common operations read naturally:

# User-friendly syntax (this fork)
camera.set_exposure(1000)          # microseconds
camera.set_gain(50)
print(camera.get_exposure())       # 1000
print(camera.get_temperature())    # 22.3  (°C, auto-converted to sensible units)

# Original / advanced syntax (still fully supported)
camera.set_control_value(asi.ASI_EXPOSURE, 1000)
camera.set_control_value(asi.ASI_GAIN, 50)
print(camera.get_control_value(asi.ASI_EXPOSURE)[0])  # 1000

See examples/demo_basic.py for the friendly style and examples/demo_advanced.py for the original style with full SDK access.

Features

• Simple, object-oriented API
• Capture images and video, adjust common parameters (exposure, gain, gamma, ROI, etc.)
• Clear documentation with step-by-step basic/advanced demos.
• Advanced features such as video mode, auto-exposure, and buffer optimization.

Quickstart

1. Install dependencies:

   • Requires the ZWO ASI SDK
     • V1.39 of the Windows SDK is included here for reference, in case the user doesn't already have it installed in a system-level path.
   • Python 3.6+
   • Common modules such as numpy, Pillow, astropy

2. Install python-zwoasi:

   pip install .

3. Set up the SDK library:

   • Set the ZWO_ASI_LIB environment variable to the path of your ASICamera2.dll/.so/.dylib, or pass it as an argument to asi.init().

4. Basic usage:

   import zwoasi as asi
   asi.init()
   cameras = asi.list_cameras()
   if not cameras:
       raise RuntimeError('No cameras found')
   camera = asi.Camera(0)
   img = camera.capture()

5. Try the example scripts:

   • examples/demo_basic.py – Minimal example showing most commonly-used features
   • examples/demo_advanced.py – Advanced features such as video mode, binning, auto-exposure, and detailed parameter inspection

Directory Structure

Path	Description
zwoasi/	Main Python package, all camera logic in __init__.py
zwoasi/examples/	Example scripts demonstrating camera usage
docs/	Sphinx documentation sources
pyproject.toml	Build and install configuration

Troubleshooting

• Make sure the ZWO ASI SDK library is accessible.
• If you get errors about missing DLL/SO/DYLIB, check the ZWO_ASI_LIB path for your system.
• For matplotlib issues, try changing the backend at the top of the demo scripts.
• For more details, see ZWO's official documentation.

License

MIT License. See LICENSE file.