The measurement of the instantaneous speed is needed in vehicles performance test.The GPS technology which is widely used in the GPS positioning is applied on the vehicle speed measurement.The SCM PIC16F877 is the core of the controller

while the E580 OEM module is used to receive GPS signals as the key component.Through software and hardware design

the GPS speed sensor which is a low-cost

high accuracy

anti-jamming performance

easy to upgrade and expand

and the data can be directly connected with data acquisition system is developed.The road test shows that the system is running fast and stable

and the results of the speed measurement is accurate.