包含了mqtt协议的底层和接口，适用于物联网开发(It includes the bottom and interface of mqtt protocol, which is suitable for the development of Internet of things.)

从网上下载的STM32 IAP源码和测试代码，已经移值到我自己的板子上，很容易，和大家共享。(Downloaded from the Internet STM32 IAP source and test code, the value has been moved to my own board, it is easy, and share.)

基于开源的PHPSIP类进行扩充改写，实现了php的SIP 客户端的基础功能，重点是扩展支持DTMF，同时支持SIPINFO模式和rfc2833协议；说起来，这个功能并不复杂，但基于对协议的理解（网上相关资料不完整），确实化了我很多时间！因为PHPSIP本身是开源的，所以我还是把自己的代码开源出来！(Extended rewriting of PHPSIP class based on open source implements the basic functions of SIP clien

sds011模块在网上开源资料较少，基本没有，在此，我将自己的51历程发布出来，供大家参考学习。希望大家也可以将自己的东西发布出来，共同学习！(Sds011 module has little open source information on the internet, basically No. Here, I will publish my 51 course for your reference and learning. Hope that you can also publish