交流电机测速程序，如果电机转速超过50转/s，则在P3.6端口蜂鸣器进行报警。-AC motor speed program, if the motor speed is more than 50 turns/s, in the P3.6 port buzzer alarm.

一个基于霍尔传感器测速并显示在LCD屏幕上的程序。-Hall sensor-based speed and displayed on the LCD screen of the program.