Create a C++ Code for Servo Read Library

For this example, create a C++ header file named ServoRead.h, and save it in the +arduinoioaddons/+ServoRead/src folder. This file wraps methods to expose to the Arduino^® library.

Include header files, including Servo.h and any other third-party header file that the add-on library depends on.
```
#include "Servo.h"
```
Create an add-on class that inherits from the LibraryBase class, which defines all the necessary interfaces.

In the constructor, define the library name, and register the library to the server.

class ServoRead : public LibraryBase
{
    public:
        Servo myServo;
    public:
        ServoRead(MWArduinoClass& a)
        {
            libName = "ServoRead/ServoRead";
            a.registerLibrary(this);
        }
...
};

The custom class and library names must have this format:

shield(vendor)/device(library)

Determine the command calls to issue from MATLAB^®.

Override the command handler, and create a switch case for each command that the add-on executes on the Arduino device:

class ServoRead : public LibraryBase
{
...
public:
        void commandHandler(byte cmdID, byte* inputs, unsigned int payload_size)
        {
            switch (cmdID){
                case 0x01:{ 
                    byte val;
                    if(!myServo.attached())
                        myServo.attach(inputs[0]);
                    val = myServo.read();
                    sendResponseMsg(cmdID, &val, 1);
                    break;
                }
                default:{
                    // Do nothing
                }
            }
        }
};

The command IDs must match up with the operations that you add to the MATLAB add-on library. For more information, see Command Handler.

(Optional) Use debugPrint to pass additional messages from the Arduino device to the MATLAB command line.

In the next section, you will Create a MATLAB Wrapper for Servo Read Library.