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libesphttpd and Micro API

libesphttpd is a HTTP server library for ESP8266. It has a fair documentation on Github and a demo. It supports common gateway interface (CGI) in C. It also has a tool to compile a collection of web pages into a binary blob which is to be flashed into ESP8266 separately from the web server codes. It can host static web files. In general, libesphttpd can be used to build a complete web server for ESP8266.

However, ESP8266 is too tiny for a full blown web server.

It is a standard practice to separate the development of web pages and a web server. In fact, due to the limited resources of the ESP8266, the web server should be kept to minimum by only exposing APIs. The web pages should be designed as the applications that run at the client side.

I wrote a micro-api framework using libesphttpd and esp-open-sdk.

Separation of concerns is important in web application development since it involves multiple stacks of tools. On the server side there will be embedded C-based tools. And on the client side there will be HTML, Javascript and CSS. The C codes for the server will have to be routinely compiled and flashed into the ESP8266 throughout the development. On the other hand, the web application development can be contained temporarily in localhost. HTML, Javascript and CSS are all scripts that do not need to be compiled. And they don't need to be flashed all the time throughout the development.

The web server is tiny. The memory is tiny. The database is as good as a flat file. Don't expect it to be an ordinary web server. The server's C codes have to be thoroughly optimized. Otherwise, the ESP8266 will be left with too little resources for it to do its embedded things.

Hence, micro API is the solution.

We can use various web frameworks on the client side. However, the total size of the files used must not reach the limit of the available flash memory in the ESP8266. Hence, we do have a development constraint on the client side. Fortunately, there are many thin front-end web frameworks for us to choose from and assemble.

Anyway, we are building the Internet of Things (IoTs). If we need a bigger web server then we should not be doing it on ESP8266.


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