地感线圈的一个射频算法,通过单片机记数器来计算频率,当有铁质物体通过线圈,线圈的电感量就会改变,从而判断有无物体.-To sense an RF coil algorithm to calculate the frequency of single-chip counter, when iron objects through the coil, the coil inductance will change, thereby to determine whether the object.