Grow Lights Control for Home Assistant AppDaemon

Copyright (c) 2025 the_louie

An AppDaemon app for Home Assistant that automatically controls growth lights based on UV index readings and seasonal time schedules.

Features

• Seasonal Time Control: Different operating hours for summer (June-August) and other months
• UV Index Monitoring: Automatically turns off lights when UV index is 5 or above
• Multiple Switch Support: Control multiple growth light switches simultaneously
• Robust Error Handling: Comprehensive logging and error recovery
• Configurable Parameters: All thresholds and sensors configurable via YAML

Time Schedules

• Summer Months (June-August): 06:00 to 18:00
• Other Months: 09:00 to 15:00

UV Index Logic

• Lights are ON during active hours when UV index is below 5
• Lights are OFF during active hours when UV index is 5 or above
• Lights are OFF outside of active hours regardless of UV index
• If UV sensor is unavailable, lights remain ON during active hours

Installation

1. Copy i1_growlights.py to your AppDaemon apps directory
2. Add the configuration to your apps.yaml or include the config.yaml file
3. Restart AppDaemon

Configuration

grow_lights:
  module: i1_growlights
  class: GrowLights

  # Time-based configuration
  off_season_start: "09:00"
  off_season_end: "15:00"
  on_season_start: "06:00"
  on_season_end: "18:00"

  # UV index configuration
  uv_index_sensor: "sensor.ecowitt_uv"
  uv_index_threshold: 5

  # Growth light switches to control
  switches:
    - switch.vaxtlampa
    - switch.vaxtlampa_fonster_vast

Configuration Parameters

Parameter	Type	Default	Description
uv_index_sensor	string	required	Home Assistant entity ID of UV index sensor
uv_index_threshold	number	5	UV index threshold for turning off lights
switches	list	required	List of switch entity IDs to control
off_season_start	time	"09:00"	Start time for non-summer months
off_season_end	time	"15:00"	End time for non-summer months
on_season_start	time	"06:00"	Start time for summer months
on_season_end	time	"18:00"	End time for summer months

Operation

The app runs the following checks every 10 minutes:

1. Determines current season (summer vs other months)
2. Checks if current time is within active hours
3. If outside active hours, ensures lights are OFF
4. If inside active hours, reads UV index and controls lights accordingly

Performance Optimizations:

• Time strings are parsed once at startup for efficiency
• Single datetime call per check cycle
• Minimal state tracking to reduce memory usage
• Early returns prevent unnecessary processing

Logging

The app provides comprehensive logging at different levels:

• INFO: Light state changes and important events
• WARNING: UV sensor unavailability
• ERROR: Configuration or operational errors
• DEBUG: Detailed state information

Error Handling

• Graceful handling of sensor unavailability
• Configuration validation on startup
• Exception logging with line numbers
• Fallback behavior when sensors are unavailable

Requirements

• Home Assistant with AppDaemon
• UV index sensor (e.g., Ecowitt weather station)
• Growth light switches or relays

License

This project is licensed under the BSD 2-Clause License - see the LICENSE file for details.