采用霍尔传感器3020T,根据霍尔效应原理,在电机转轴边沿上放一永久磁钢,转轴附近放一个别3020T,当转轴旋转时,受磁钢的影响,霍地尔器件输出脉冲信号,送至单片机中断引脚,转速计数加1,单片机内部产生5s的定时,计算出1分钟的转速,送至显示单元,-Using Hall sensors 3020T, according to Hall-effect principle, the motor shaft of a permanent magnet placed on the edge, do not put a shaft near the 3020T, when the shaft rotates by magnet effect, HUO Di Seoul device output pulse signal, sent to microcontroller interrupt pin, speed count plus 1, the microcontroller internally generated timing 5s to calculate the speed of 1 minute, sent to the display unit,