Design and Implementation of Real-time Digital Display Speed Measurement Equipment

This paper present a simple real-time digital display speed measurement device,the speed device works by using the photodiode light-sensitive properties,when the direct rays of light when the turn,no light irradiation end.After data processing by the microcontroller AT89C2051 get speed,coupled with digital control and keypad matrix driver chips HD7279A operation to display the speed and better control,through specific project applications were explained in detail from both hardware and software.