# HomeSpan Overview

*Note: This page references a lot of HomeKit HAP terminology.  If you are new to HomeKit development, you may want to start by first reviewing the [HomeKit Primer](HomeKitPrimer.md) page.*

HomeSpan is an Arduino-style C++ library designed for ESP32 devices to take on the role of a *HAP Accessory Server* (i.e. a HomeKit Device), which allows the device to be paired to, and communicate with, any *HAP Client*, such as Apple's Home App on an iPhone, iPad, or Mac.

There are three primary components of HomeSpan:

1. **The HomeSpan API** - a collection of objects, methods, and functions you implement inside an Arduino-style sketch to create your HomeKit device.

1. **The HomeSpan Command-Line Interface (CLI)** - a series of diagnostics that HomeSpan outputs to the Arduino Serial Monitor, and a series of command you can enter into the Serial Monitor to request more diagnostic information, to perform some basic housekeeping functions (e.g. a Factory Reset), and to configure the device with WiFi Credentials and a HomeKit Setup Code.

1. **An End-User Environment** - allows an end-user to configure a standalone HomeSpan device using only a simple Control Button and the device's Status LED

### Creating a HomeSpan Sketch

The structure of a HomeSpan sketch is as follows:

```C++
#include "HomeSpan.h"         // include the HomeSpan library

void setup() {     
 
  Serial.begin(115200);       // start the Serial interface
  
  /// HOMESPAN SETUP CODE ///
  
} // end of setup()

void loop(){

/// HOMESPAN LOOP CODE ///

} // end of loop()
```


Need to discuss development environment

Need to discuss micro-controller usage to connect to real-world devices (not to connect to other web servers)

Need to discuss control button and status led

Need to discuss configuring using the CLI and the WiFi Access Point

Overview of programming paradigm

Point to the tutorials

Point to the HomeSpan Library Reference