设计一个测距器，可以应用于汽车倒车、建筑施工工地以及一些工业现场的位置监控，也可用于如液位、井深、管道长度的测量等场合。-The design of a range-finder, can be applied to vehicles reversing, construction site, as well as the location of some industrial-site monitoring, can also be used such as liquid level, dep

超声波报警程序，用超声波对距离进行检测，可做倒车时距离的检测-Ultrasonic Alarm

汽车后窗LED显示屏51程序，当汽车转向，刹车，倒车，双闪时后窗LED平做相应的文字和符号提示，平时显示日期，时间及公益广告等.有实际应用。-Car back-windows LED display