UV (ultraviolet) sensors of all sorts have been an interest of mine. They become interesting when you find the diversity of real-world practical applications. While searching for affordable UV light ...

The LTR-390, in contrast, does have a real light sensor in the UV spectrum. It’s also got a much much simpler I2C interface so you can run it on the Arduino or Python microcontrollers ...

Applications are foreseen with phone cameras for white-balance, artificial/natural/outdoor light discrimination and flicker frequency measurement – the latter to avoid banding and set exposure time.