Dim lights when TV turns on
Enhance movie watching by automatically dimming lights when the TV turns on. Create the perfect viewing atmosphere without fumbling for light switches.
Use cases
Entertainment
- Movie Watching - Optimize lighting for better screen visibility
- TV Show Viewing - Reduce glare and eye strain
- Gaming - Create immersive gaming environment
Comfort & Ambiance
- Afternoon Viewing - Close blinds when sun hits screen
- Theater Experience - Automatic cinema mode in your living room
Products needed
Essential Equipment - Option 1: Power Monitoring (Most Universal)
Real-time power measurement • Relay control
Essential Equipment - Option 2: Smart TV Integration (More Reliable)
Works with: Home Assistant, SmartThings
Dimmable capability required
Optional Enhancements
Basic automation setup
Using Power Monitor
Trigger: Smart plug power consumption rises above 50 watts (TV turns on)Conditions: Time between sunset and sunrise (optional)
Actions: Dim lights to 10% OR turn off completely • Optional: Close blinds/curtains
Using Smart TV
Trigger: TV turns on OR specific app opens (Netflix, Disney+, etc.)Conditions: Time between 6 PM - midnight (movie hours) • Only for video apps
Actions: Dim lights to 10-20% • Close blinds if daytime
Platform-specific examples
Home Assistant
SmartThings
Hubitat
Apple HomeKit
Alexa
Google Home
Advanced features
Content-aware lighting
Different content types get different lighting:
Create automation triggered by TV app changes with conditional logic:
- Movie mode (Netflix, Disney+, Plex): 5% brightness, warm white, close blinds
- TV show mode (Hulu, YouTube TV): 15% brightness
- Gaming mode (HDMI inputs): 25% brightness, activate RGB bias lighting with dynamic effect
- Sports mode (ESPN): 30% brightness
Use app name or input source to determine content type and adjust accordingly.
Daytime glare control
Different behavior for daytime vs nighttime:
Create two automations:
Daytime (sunrise to sunset):
- Close blinds to reduce glare
- Keep lights at 40% (more light needed during day)
Nighttime (after sunset):
- Dim lights significantly to 10%
- Blinds already closed or less critical
Bias lighting synchronization
Sync LED strip behind TV:
- Dim main room lights to 5%
- Activate TV backlight LED strip at 50% brightness
- Set warm white/orange color (RGB: 255, 140, 60)
Pause dimming for movement
Don’t dim if people are moving around:
Add condition: No motion detected in last 5 minutes before dimming lights
Troubleshooting
Issue: Lights dim when TV menu on
Causes:
- Power monitoring can’t differentiate between menu and playback
- Trigger threshold too low
- No delay to ensure actually watching content
Solutions: ✅ Increase power threshold (try 80W instead of 50W) ✅ Add longer delay (30 seconds) before dimming ✅ Use smart TV integration instead - detect ‘playing’ state ✅ Add condition: Only between certain hours (6 PM - midnight) ✅ Use app-specific triggers (Netflix/Disney+ only)
Issue: Lights don’t restore when TV off
Causes:
- Power drops gradually, not instantly
- No reverse automation created
- Previous brightness not saved
- TV on standby still drawing power
Check:
- ✅ Create separate “restore lights” automation (shown in examples)
- ✅ Use lower power threshold for “off” detection (below 10W)
- ✅ Add 2-minute delay to ensure TV actually off (not just paused)
- ✅ Save previous light state before dimming
- ✅ Test actual TV power consumption when off (may be 5-15W)
Fix with state saving:
- When dimming: Create scene snapshot of current light state, then dim
- When restoring: Activate saved scene to restore exact previous brightness
Issue: Smart TV state inaccurate
Causes:
- TV integration losing connection
- TV firmware outdated
- Network issues
- Platform doesn’t support TV model well
Solutions: ✅ Update TV firmware to latest version ✅ Check TV integration in platform (reconnect if needed) ✅ Use power monitoring as backup method ✅ Restart hub/integration ✅ Check TV is on same network as hub ✅ Use Cast device (Chromecast) instead of TV direct integration
Related automations: