First generation: handwritten white paper version or printed paper version: This is the earliest form of paper parking signs, usually made by handwriting or printing, with a handwritten mobile phone number on it.
Industrial second generation: produced by mold processing, with two materials, plastic and metal, and more standardized and durable.
Third generation of electronic screens: including micro central controllers, display driver chips and electronic display screens, with richer and more modern functions.
Fourth generation with integrated motion sensors: motion sensors are added to make parking signs more intelligent.
Fifth generation of Bluetooth smart: combined with Bluetooth technology, a higher level of intelligence and interconnection functions are achieved.
