# Packages
# README
Sunlight Meter
Using the Adafruit TSL2591 Digital Light Sensor and a Raspberry Pi to monitor daily sunlight conditions.
About
The TSL2591 is a high dynamic range digital light sensor.
It can detect infrared, full-spectrum and human-visible light, then transmit that data over a serial connection.
Features:
- Monitors the current light conditions.
- Reports real-time data for monitoring or automation.
- Saves historical data to give insight on changes over time.
- Provides a dashboard to control the sensor and visualize data.
- Determines if your location is: ☁️ shade, partial shade, partial sun, or full sun ☀️
How it works
Configuration:
The TSL2591 sensor is connected to a Raspberry Pi via i2c.
Connecting the sensor to the Pi:
- Vin to 3.3V
- GND to GND
- SDA to SDA
- SCL to SCL
Sunlight Meter automatically adjusts sensor gain and integration time.
This helps ensure accurate readings and avoid saturation in high light conditions.
API:
Sunlight Meter runs an API that allows remote access to the sensor data and jobs.
Connect remotely to:
- Start/Stop any recording job.
- Receive real-time readings and light conditions.
- Download historical data as a SQLite DB.
- Check device wifi-signal strength.
Dashboard:
The dashboard is a web app that displays the current light conditions and historical data.
- Visualize historical light conditions
- Control the sensor
- Export the results
Understanding Lux Values
From https://en.wikipedia.org/wiki/Lux:
| Illuminance (lux) | Surfaces illuminated by |
|---|---|
| 0.0001 | Moonless, overcast night sky (starlight) |
| 0.002 | Moonless clear night sky with airglow |
| 0.05–0.3 | Full moon on a clear night |
| 3.4 | Dark limit of civil twilight under a clear sky |
| 20–50 | Public areas with dark surroundings |
| 50 | Family living room lights |
| 80 | Office building hallway/toilet lighting |
| 100 | Very dark overcast day |
| 150 | Train station platforms |
| 320–500 | Office lighting |
| 400 | Sunrise or sunset on a clear day |
| 1000 | Overcast day; typical TV studio lighting |
| 10,000–25,000 | Full daylight (not direct sun) |
| 32,000–100,000 | Direct sunlight |