测量转速，使用霍尔传感器，被测轴安装有1只磁钢，即转轴每转一周，产生1个脉冲，要求将转速值，显示在数码管上。-Measurement speed, the use of Hall sensors, the measured shaft with a magnet, that is, turn the shaft of each week generates a pulse and requested speed value displayed on the digital pipe.