短信发送分两种方式，一种是TEST，一种就是PDU，PDU是一种编码方式，本文是用TEXT编码方式进行编辑，通过单片机实现短信的发送与接收，-SMS are two methods for a TEST, a is the PDU, PDU is an encoding, this encoding is to use TEXT for editing, through the MCU to send and receive text messages,