Update Overview.md

docs/Overview.md

@@ -8,13 +8,13 @@ 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. **The HomeSpan Command-Line Interface (CLI)** - a series of diagnostics that HomeSpan outputs to the Arduino Serial Monitor, and a series of commands you can enter into the Serial Monitor to request more diagnostic information, to perform some basic housekeeping functions (such as 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
+### Overview of the HomeSpan API
 
-The structure of a HomeSpan sketch is as follows:
+The basic structure of a HomeSpan sketch is as follows:
 
 ```C++
 #include "HomeSpan.h"         // include the HomeSpan library
@@ -23,19 +23,39 @@ void setup() {
  
   Serial.begin(115200);       // start the Serial interface
   
-  /// HOMESPAN SETUP CODE ///
+  /// HOMESPAN SETUP CODE GOES HERE ///
   
 } // end of setup()
 
 void loop(){
 
-/// HOMESPAN LOOP CODE ///
+  /// HOMESPAN LOOP CODE GOES HERE ///
 
 } // end of loop()
 ```
 
+Inclusion of HomeSpan.h creates a global object called `homeSpan` that implements a variety of methods.  The two most important are `begin()` and `poll()`.  The `begin()` method, which takes a number of optional parameters, initializes HomeSpan and is placed near the begining of the `setup()` section.  The `poll()` method, which take no arguments, is placed inside `loop()` and is what causes HomeSpan to run all its code.  This is generally the only function placed in the `loop()` section.  Our sketch now looks like this:
+
+```C++
+#include "HomeSpan.h"         // include the HomeSpan library
+
+void setup() {     
+ 
+  Serial.begin(115200);       // start the Serial interface
+  
+  homeSpan.begin();           // initialize HomeSpan
+  
+  /// CONFIGURATION OF ACCESSORY ATTRIBUTE DATABASE GOES HERE ///
+  
+} // end of setup()
+
+void loop(){
+
+ homeSpan.poll(); 
+
+} // 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)