Language - Ruby

Ruby is an interpreted and object oriented scripting language with simple syntax created by Yukihiro Matsumoto.

Introduction

If this is your first time working with a Phidget, we suggest starting with the Getting Started page for your specific device. This can be found in the user guide for your device. That page will walk you through installing drivers and libraries for your operating system, and will then bring you back here to use Ruby specifically.

Ruby is capable of using the complete Phidget API, including events. We also provide example code in Ruby for all Phidget devices.

Ruby can be developed with Linux and OS X.

You can compare Ruby with our other supported languages.

Quick Downloads

Just need the Ruby documentation, drivers, libraries, and examples? Here they are:

API Documentation

• API Manual

Library and Example Code

• phidgets-ffi @ RubyGems

Drivers

• Linux Source
• OS X Drivers Installer

Getting started with Ruby

If you are new to writing code for Phidgets, we recommend starting by running, then modifying existing examples. This will allow you to:

• Make sure your libraries are properly linked
• Go from source code to a test application as quickly as possible
• Ensure your Phidget is hooked up properly

Instructions are divided up by operating system. Choose:

• OS X
• Linux (including PhidgetSBC)

OS X

Ruby has excellent support on OS X through the Mono framework.

The first step in using Ruby on Mac is to install the Phidget libraries. Compile and install them as explained on the getting started guide for your device. Then, the OS - OS X page also describes the different Phidget files, their installed locations, and their roles....

Description of Library Files

Ruby programs on Windows depend on the following files, which the installers above put onto your system:

• phidget21.dll contains the actual Phidgets library, which is used at run-time. By default, it is placed in C:\Windows\System32.

You will also need one of the following two files, depending on the .NET framework version you are targeting:

• /lib is the Phidgets library for .NET framework 2.0 or higher. Your compiler has to know where this file is. By default, it is placed into C:\Program Files\Phidgets. You can either point your compiler to that location, or copy and link to it in a directory for your project workspace.
• examples is the Phidgets library for .NET framework 1.1. Your compiler has to know where this file is. By default, is is placed into C:\Program Files\Phidgets. You can either point your compiler to that location, or copy and link to it in a directory for your project workspace.

If you do not want to use our installer, you can download the five file files.

Running the examples and writing your own code can be fairly compiler-specific, so we include instructions for each compiler below.

Visual Studio 2005/2008/2010

Microsoft makes free versions of Visual Studio available known as Express Editions. The Express editions are suitable for most applications, but are limited in features for more complex applications. Please see Microsoft Visual Studio for more information.

Use Our Examples

Please start by downloading the examples and unpack them into a foler. While these examples were written in Visual Studio 2005 and 2008, Visual Studio 2010 will easily open and upgrade them. To load all projects in Visual Studio, go to File → Open → Project, and open AllExamples/AllExamples.sln or AllExamples/AllExamples_vs2008.sln for Visual Studio 2005 and 2008, respectively.

If you are opening the Phidget examples in Visual Studio 2010, you will need to go through the Visual Studio Conversion Wizard to convert the 2005 or 2008 project.

This will load all of the examples available for Ruby, and then you can set your main project to be the one that matches your device. If you aren't sure what the software example for your device is called, check the software object listed in the Getting Started guide for your device.

The only thing left to do is to run the examples! Click on Debug → Start Debugging. Please note that the projects, by default try to find the Phidget21.NET.dll in the C:\Program Files\Phidgets. If you have it installed in another location, please change the path to the file's location accordingly. If you are receiving an error message regarding that the namespace Phidgets cannot be found, please re-add the reference to Phidget21.NET.dll. Please see the Write Your Own Code section for details.

Once you have the Ruby examples running, we have a teaching section below to help you follow them.

Write Your Own Code

When you are building a project from scratch, or adding Phidget function calls to an existing project, you'll need to configure your environment to properly link the Phidget Ruby libraries. To begin:

1. Generate a new Ruby Windows Applications project with a descriptive name such as PhidgetTest.

2. Add a reference to the .NET Phidgets library.

3. Under the .NET tab, select Phidget21.NET.dll. If you used our installer, these files are installed in C:\Program Files\Phidgets, by default. If it does not appear in this list, then you can browse to the Phidget Framework installation directory and add the file.

4. Then, in your code, you will need to include the Phidget library:

  using Phidgets;
  using Phidgets.Events;

The project now has access to the Phidget21 function calls and you are ready to begin coding.

The same teaching section which describes the examples also has further resources for programming your Phidget.

Linux

C# has support on Linux through the Mono framework.

The first step in using Ruby on Linux is to install the Phidget libraries. Compile and install them as explained on the main Linux page. That Linux page also describes the different Phidget files, their installed locations, and their roles.

Follow the Examples

By following the instructions for your operating system and compiler above, you probably now have a working example and want to understand it better so you can change it to do what you want. This teaching section has resources for you to learn from the examples and write your own.

Next, comes our API information. These resources outline the Ruby Phidget functions:

• Ruby API (This is the complete set of functions you have available for all Phidgets)
• Device Specific APIs - The one for your Phidget can be found in its user guide.

To learn the details behind opening, configuring, using, and closing your Phidget, try the General Phidget Programming page. That page also describes using the Phidget in an event-driven manner and in a traditional manner, both of which are available in Ruby.

Example Flow

The Hello World example has this general structure so you can follow along. We also have an in-depth general introduction to writing Phidget code (like open, read data, etc), as well as the Ruby API for specific syntax:

// ----- Event and Other Functions ----- Create any Language-Specific Functions (exception handling) Create General Attach, Detach, and Error Handling Functions: On attach: Print Hello Message On detach: Print Goodbye Message		In Ruby, you can name these event functions whatever you like. You will then pass them as function pointers to the Phidget library below in the Main Code section. This hooks them into the actual events when they occur. In the example code, the event functions common to all Phidgets are called things like AttachHandler() and DetachHandler(), etc. Some event functions will be specific to each device, like when a tag is read on an RFID board, or when a sensor value changes on an Interface Kit. Other functions are given in the examples to show you more detail on using your Phidget. For example, DeviceInitialize() will show what needs to be set up for your Phidget before using it.
// ----- Main Code ----- Create Manager Software Object Hook Event Functions created above to Device Open Device Wait for 'Enter' key character input Handle on-going attach and detach events Print Hello and Goodbye messages Exit upon input Close Device Delete Device		Creating a Phidget software object in Ruby is specific to the Phidget. For a Phidget Spatial, for example, this would involve creating a Spatial object. The examples show how to do this and other API functions. The object provides device specific methods and properties which are available from the API for your specific Phidget.

Common Problems and Solutions/Workarounds

Here you can put various frequent problems and our recommended solutions.