测速.用于霍尔传感器测数，这个代码是用来提高精确度的-it is a code to develop accuratity 。dut it is very short ,you maydisappointed.i am very very very sorry.

如何利用单片机模拟霍尔脉冲，实现测速功能-How to use single-chip analog Hall pulses, to achieve speed function