此程序为同学的毕业设计《倒车雷达》超声波测距+1602液晶显示，具有当所测量距离越短器蜂鸣发出的频率不断变化，可以通过蜂鸣器的响声来判断障碍物的距离远近-This program is designed to graduate students, " reversing radar" Ultrasonic Ranging+1602 LCD, with the shorter the distance when the measured device beeps emitted