Observatory Journal
Measuring Outdoor Light with BH1750
The BH1750 light sensor becomes one of the core signals of the observatory, helping distinguish daylight, darkness and changing sky conditions.
Light as a sky signal
Outdoor light level is one of the most useful signals for a small observatory.
It helps distinguish day, night, twilight, cloud cover changes and sudden variations in sky brightness.
The BH1750 node
The BH1750 sensor is connected to an ESP32 node that reads lux values and sends them to the backend.
The sensor is simple, but the value becomes powerful when stored historically and compared with time of day and weather conditions.
Why it became a core measurement
Lux data gives the dashboard a direct connection to what is happening outside.
It is also one of the first custom measurements fully controlled by the observatory system.