背景：最近整理东西，发现了一个蓝色的小模块，上面还有两个像喇叭的小东西，关键上面还有丝印，用蓝底白字写着“HC-SR04”，于是勾起了我的好奇心，动动小手指，百度找到了这个小板子的信息，原来是一个超声波测距模块，还挺有意思的，而且只引出来了四个引脚，应用也比较简单，下面简单介绍下这个模块以及简单的超声波测距方案。

[Clint] was working with the Arduino library, based on the Parallax PING, which uses a single pin for trigger and echo. The HC-SR04 uses separate pins.

Posted in Arduino Hacks Tagged arduino, balance, HC-SR04, pid, sonar ← Danielle Applestone And The Story Of Every Othermill NFC Tags Add Old-School Functionality To New Phone → ...