Sun Shade Integration for Home Assistant

A Home Assistant custom integration that uses 3D ray-casting simulation to determine when direct sunlight reaches indoor plants through windows.

                        * Sun
                       /
                      /  azimuth + elevation
                     /
   =================/=================
   ||    WALL    |     |    WALL    ||
   ||            |     |           ||          OUTSIDE
   ||            |  W  |           ||
   ||            |  I  |           ||
   ||            |  N  | ray       ||
   ||            |  D  |/          ||
   =============|  O  |============/
                |  W  |\
                |     | \            +------------------------------+
                +-----+  \          |  Home Assistant Entities      |
                       \  \         |------------------------------|
                    /---\--\        |  window_1a has sun:  ON       |
       ROOM        | //  \ |       |  window_1a intensity: 78%     |
                   | PLANT |       |  window_1a angle:    25 deg   |
                   | \\  / |       |                               |
                   +-------+       |  Plant sun start:  13:45      |
                                   |  Plant sun end:    15:30      |
                                   |  Plant sun duration: 120 min  |
                                   +-------------------------------+

Entities Created

Per window (real-time, updated every N seconds):

• binary_sensor.<window>_has_sun — whether the window is receiving direct sunlight
• sensor.<window>_sun_intensity — intensity factor (0-100%)
• sensor.<window>_sun_angle — angle between sun and window normal (0-90 deg)

Plant-level (daily forecast, computed once per day):

• sensor.plant_sun_start — first time sun hits the plant today (like sunrise)
• sensor.plant_sun_end — last time sun hits the plant today (like sunset)
• sensor.plant_sun_duration — total sun exposure in minutes (like day length)

Installation

HACS (Recommended)

1. Open HACS in your Home Assistant instance
2. Click the three dots in the top right corner and select Custom repositories
3. Add https://github.com/matiazo/SunHitsIndoorPlant3DSimulator with category Integration
4. Click Install
5. Restart Home Assistant
6. Go to Settings > Integrations > Add Integration and search for "Sun Shade Integration"

Manual

1. Copy the custom_components/sun_shade_integration folder into your Home Assistant config/custom_components/ directory
2. Restart Home Assistant
3. Go to Settings > Integrations > Add Integration and search for "Sun Shade Integration"

Documentation

See the full integration docs at custom_components/sun_shade_integration/README.md for config flow details, entity reference, and troubleshooting.