2025-08-28 00:00:00 When the ambient brightness detected by the brightness sensor mounted on the smartphone becomes darker than the specified value, the light is automatically turned on. When it becomes brighter than the specified value, the light is automatically turned off. Think for yourself what you use this for. For example, when fixing a smartphone to the handlebar of a bicycle. Even if you turn off the screen of your smartphone, you can keep the light on and off.