In computer programming, an application programming interface (API) is a set of subroutine definitions, protocols, and tools for building application software. In general terms, it is a set of clearly defined methods of communication between various software components. A good API makes it easier to develop a computer program by providing all the building blocks, which are then put together by the programmer.

An API may be for a web-based system, operating system, database system, computer hardware or software library. An API specification can take many forms, but often includes specifications for routines, data structures, object classes, variables or remote calls. POSIX, Windows API and ASPI are examples of different forms of APIs.

On this week i am going to interface both hardware device and software by using ESP8266 NodeMCU board by switch ON and OFF LED

Design Circuit Board

On this week i try to design circuit board but it doesn't work.Because of bad connection that problem i was identify.

This is the firrst design i try to make but it doesn't work.

But again I try to design new ESP8266 experimental board in order to complete my assignment.Now it work very well.

ESP8266 NodeMCU and Protocol

The ESP8266 WiFi Module is a self contained SOC with integrated TCP/IP protocol stack that can give any microcontroller access to your WiFi network. The ESP8266 is capable of either hosting an application or offloading all Wi-Fi networking functions from another application processor.

There are mainly two protocols that make up this third layer: the Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP). TCP makes sure that all packets are received, that the packets are in order, and that corrupted packets are re-sent.more about protocol

ESP8266 NodeMCU pinout

Programming

On programming i try to program both C programming language and HTML language in Arduino ide.

For C programming i use in order to program hardware device include input and output , set server ON and again i used to connect on the access point which in range.

For HTML i use for making web page which include ON and OFF button in order to control hardware device like Led or Relay.

C Programming language on Arduino ide

HTML language on Arduino ide

How web page look like

Testing

Here you can download all file on this week Download the files here