Healthy Monitor

A Rust application that automatically adjusts your monitor's brightness and color temperature based on:

1. Webcam light sensor (primary method)
2. Weather data and time of day (fallback method)

Features

• Automatic brightness adjustment based on ambient light
• Color temperature adjustment based on time of day
• Configurable monitor settings
• Fallback to weather-based brightness when webcam is unavailable
• Customizable minimum brightness and color temperature settings

Prerequisites

• Linux system with X11
• xrandr command-line tool
• Webcam (optional)
• Rust and Cargo

Installation

Install directly from crates.io:

cargo install healthy-monitor

Usage

Basic usage (using webcam):

healthy-monitor

If webcam is not available, provide OpenWeather API key:

healthy-monitor --api-key YOUR_API_KEY

Command Line Options

healthy-monitor [OPTIONS]

Options:
    --api-key <API_KEY>            OpenWeather API key (required only if webcam is not available)
    --min-brightness <FLOAT>       Minimum brightness level (0.0 to 1.0) [default: 0.6]
    --day-temp <FLOAT>            Color temperature during day in Kelvin [default: 6500]
    --night-temp <FLOAT>          Color temperature during night in Kelvin [default: 3500]
    --transition-hours <FLOAT>     Hours before sunset to start transitioning [default: 2.0]
    --monitors <MONITORS>          Comma-separated list of monitor names [default: autodetect]
    -h, --help                     Print help
    -V, --version                  Print version

Examples

1. Basic usage with webcam:

healthy-monitor

2. Custom brightness and monitors (with webcam):

healthy-monitor \
    --min-brightness 0.4 \
    --monitors "HDMI-1,DP-1"

3. Using weather API (when webcam is unavailable):

healthy-monitor \
    --api-key YOUR_API_KEY \
    --min-brightness 0.4

Automatic Execution with Crontab

To run healthy-monitor automatically at regular intervals:

1. Find the path to the installed binary:

which healthy-monitor

2. Open your crontab configuration:

crontab -e

3. Add one of these example configurations:

# Run every 5 minutes (with webcam)
*/5 * * * * DISPLAY=:0 /path/to/healthy-monitor

# Run every 5 minutes (with weather API fallback)
*/5 * * * * DISPLAY=:0 /path/to/healthy-monitor --api-key YOUR_API_KEY

# Run every 10 minutes during daytime with custom settings
*/10 7-22 * * * DISPLAY=:0 /path/to/healthy-monitor --min-brightness 0.4 --monitors "HDMI-1,DP-1"

Note:

• Replace /path/to/healthy-monitor with the actual path from step 1
• Replace YOUR_API_KEY with your OpenWeather API key
• The DISPLAY=:0 is required for X11 access
• Adjust the timing pattern (the five fields at the start) as needed:
  • */5 means "every 5 minutes"
  • 7-22 means "from 7 AM to 10 PM"
  • See man 5 crontab for more timing patterns

Monitor Configuration

To find your monitor names, run:

xrandr --listmonitors

Then use these names in the --monitors option.

How It Works

1. The application first attempts to use your webcam to measure ambient light.
2. If the webcam is unavailable, it falls back to using weather data:
   • Fetches your location using IP geolocation
   • Gets weather data from OpenWeather API
   • Calculates brightness based on time of day and cloud coverage
3. Adjusts monitor brightness and color temperature using xrandr
4. Color temperature transitions gradually from day to night

License

MIT License