Language - C

Support

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 C/C++ specifically.

C/C++ is capable of using the complete Phidget API. We also provide example code in C/C++ for all Phidget devices.

C/C++ can be developed with various Windows compilers (including Borland), Mac OSX, and Linux.{{{5}}}

You can compare C/C++ with our other supported languages.

Quick Downloads

Just need the C/C++ drivers, libraries, and examples? Here they are:

C/C++ API Documentation:

• C/C++ API Manual Download or (HTML online version)
• General API (more help on functions common to all Phidgets)
• Device Specific APIs (more help on functions specific to your Phidget)

C/C++ Example Code:

• C/C++ Example Code for Windows
• C/C++ Example Code for Linux/MacOS

Libraries and Drivers:

• 32 bit Windows (drivers, with libraries)
• 64 bit Windows (drivers, with libraries)
• Borland C++ Libraries (You also need one of the two Windows drivers above)
• General Linux Libraries ( Linux Library Setup Instructions)
• General Mac OSX Libraries ( Mac OSX Library Setup Instructions)

Getting Started (Windows)

Run The Examples

A good way to learn to use Phidgets is to run and modify existing examples. You can find the C/C++ API and example code here:

• C/C++ API Reference
• Microsoft Visual C/C++ Examples
• Standard C/C++ Examples

To run the example code, you'll need to find the source code for your specific device within the example package. Then, compile the code under your platform and run it. 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

The Phidget examples were written using Visual C++ 2005. They also work well in other, similar environments such as Visual Studio.

Specific setup for many other compilers is covered below. Often, you can just import the example as an existing project, but if you are having trouble it might help to read the Write Your Own Code section below for your specific compiler.

Follow The Examples

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 {{{3}}} 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		{{{1}}}
// ----- 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		{{{2}}}

Write Your Own Code (Windows)

• C/C++ 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 C/C++.

These Windows sections below need additional information

General Windows Library Setup

• 32 bit Windows (drivers, with libraries)
• 64 bit Windows (drivers, with libraries)

In addition to actually creating code to drive your Phidget, you will also need to properly link the Phidget C/C++ libraries, which are included with the drivers above. Most compilers provide their own documentation on how to link external libraries. (Note that for Borland, you'll need a different library, which you can find in the Borland section below).

Then, in your code, you usually need to include the Phidget library specifically:

  #include "phidget21.h"

Visual C++ 2005 Library Setup

To link libraries in Visual C++ 2005:

• Generate a new C/C++ console project with a descriptive name such as PhidgetTest.
• Copy phidget21.h and phidget21.lib from the VC/VC++/Borland examples and add them to your project directory.
• Open the project properties window.
• Navigate to Configuration Properties | Linker | Input.
• Edit the additional dependencies and add “phidget21.lib”.

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

Borland C/C++ Library Setup

To link libraries in Borland C/C++:

Make sure to download the additional Borland-specific libraries in addition to the drivers you already have through the Getting Started page for your device:

• Borland C++ Libraries

Create and Build Your Project

This section may also require expansion into individual compilers

With the libraries linked properly in your compiler, you can consult the following resources for help with writing code:

• C/C++ API Manual Download or (HTML online version)
• General API (more help on functions common to all Phidgets)
• Device Specific APIs (more help on functions specific to your Phidget)

• The page with general programming concepts for Phidgets

Build and compile your project with the properly linked libraries as you would any project on your specific compiler.

Getting Started (MacOS/Linux)

Run The Examples

One good way to start developing your application is to run and modify existing examples. You can find the C/C++ API and example code here:

• C/C++ API Reference
• Standard C/C++ Examples for Linux/MacOS

To run the example code, you'll need to find the source code for your specific device. Then, compile the code under your platform and run it. 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

The examples assume that the compiled libraries have been set up properly.

• To set them up on Mac OSX, follow the Getting Started page for your specific device
• To set them up on Linux, compile and install them as explained on the main Linux page

Compiling and linking against the Phidgets Library for the example code can be done in the following ways:

To build on Linux:

  gcc example.c -o example -lphidget21

To build on MacOS (for example, depending on the Headers location):

  gcc example.c -o example -framework Phidget21 -I/Library/Frameworks/Phidget21.framework/Headers

Follow The Examples

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 {{{3}}} 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		{{{1}}}
// ----- 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		{{{2}}}

Write Your Own Code (Mac OSX/Linux)

• C/C++ 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 C/C++.

General Mac OS/Linux Library Setup

Before you can use the Phidget, you must include a reference to the library header.

  #include <phidget21.h>

Create and Build Your Project

With the libraries linked properly in your compiler, you can consult the following resources for help with writing code:

• C/C++ API Manual Download or (HTML online version)
• General API (more help on functions common to all Phidgets)
• Device Specific APIs (more help on functions specific to your Phidget)

• The page with general programming concepts for Phidgets

Compiling and linking against the Phidgets Library can be done in the following ways:

To build on Linux:

  gcc example.c -o example -lphidget21

To build on MacOS (for example, depending on the Headers location):

  gcc example.c -o example -framework Phidget21 -I/Library/Frameworks/Phidget21.framework/Headers

Development Environments and Compilers

Describe each major compiler and notable differences or important information. (eg. framework versions) If there are known issues/workarounds mention them and link to the corresponding issue at the bottom of the page.

This section may or may not be covered in the different compilers sections above in Getting Started (Windows), and the common problems below? If so, delete this section.

Common Problems and Solutions/Workarounds

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