Measurement Method of Motor Speed Based on Microcontroller and 8254 Interval Timer

The speed measurement circuit is typically composed of a microcontroller and 8254 Interval timer,and the alterable sample periods algorithm is applied,which could realize high-accurate and real-time measurements. The modes and control words of 8254 timer are introduced.Two measurement algorithm are compared,a simplified method based on the characteristics of microcontrollers and the measurement specifications is proposed,which had the features of less resources occupation,simple algorithm and alterable modes of 8254 timer as the motor speed changing.