Language - C

From Phidgets Support

Icon-C++.png C++ is a general purpose, cross-platform programming language with a vast user base.

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Quick Downloads

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

C/C++ API Documentation:

C/C++ Example Code:

Libraries and Drivers:

Getting started with C/C++

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:

Windows

C/C++ programs on Windows depend on three files, which the installers above put onto your system:

  • Phidget21.dll contains the actual Phidgets library, which is used at run-time. If you used our installer, it's already correctly placed in C:\Windows\System32. It can be manually installed - check our Manual Installation instructions.
  • Phidget21.lib is used by your compiler to link to the dll. Your compiler has to know where this file is. Our installer puts Phidget21.lib into C:\Program Files\Phidgets -Could be wrong-. Phidget21.lib is written to be compatible with most compilers - but your specific compiler may need a different format. Check our documentation for your specific compiler below for details.
  • Phidget21.h lists all the Phidget API function calls available to your code. Your compiler also has to know where this file is. By default, our installer puts Phidget21.h into C:\Program Files\Phidgets so you can either point your compiler to that location, or copy and link to it in a directory for your project workspace. We offer some instruction below, by compiler.

Generally, to run the examples, you will download them and unpack them into a folder. If you browse around within the examples, you'll note that the examples are specific to each Phidget. So, you'll need to find the source code for your specific device within the example package.

When you are building a project from scratch, you will need to properly link the Phidget C/C++ libraries described above. Most compilers provide their own documentation on how to link external libraries. For some compilers, such as Borland and Dev C++, you will need to use different libraries. Please check your compiler section below to see if something specific is needed. Then, in your code, you usually need to include the Phidget library specifically: 

  #include <phidget21.h>

Visual Studio


Visual Studio 2010

Visual Studio 2008

Visual Studio 2005

Visual Studio 2003

Visual Studio 6

Borland

GCC on Windows


CygWin

MinGW

Dev C++




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General Windows Library Setup

In addition to actually creating code to drive your Phidget,


Visual Studio C++ Library Setup

To link libraries in Visual C++ 2005:

  • Generate a new C/C++ console project with a descriptive name such as PhidgetTest.
  • Open the project properties window.
  • Navigate to Configuration Properties | C/C++
  • Add "C:\Program Files\Phidgets" to the additional directories field.
  • Navigate to Configuration Properties | Linker | Input.
  • Edit the additional dependencies and add "C:\Program Files\Phidgets\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:

To compile and link your program: bcc32 -I"C:\Program Files\Phidgets" -L"C:\Program Files\Phidgets" phidget21bcc.lib example.c

MinGW Library Setup

To compile and link your program: gcc example.c -I"C:\Program Files\Phidgets" -L"C:\Program Files\Phidgets" -lphidget21

Cygwin Library Setup

To compile and link your program: gcc example.c -I"/cygdrive/c/Program Files/Phidgets" -L"/cygdrive/c/Program Files/Phidgets" -lphidget21

Dev C++ Library Setup

In order to control Phidgets with Dev-C++, the library file will need to be in a format that Dev-C++ accepts, as described in the following steps. The following steps works with Dev-C++ 4.9.9.2. Download the reimp tool(Please download it here), and type the following command to create libphidget21.a. 

reimp.exe "C:\Program Files\Phidgets\phidget21.lib"

Place libphidget21.a in <Dev-Cpp Install Directory>/lib

Open up your project in Dev-C++, and traverse to Project Options->Parameters->Linker, and enter the following to link to the library: 

-lphidget21

Next, the path to phidget21.h will need to be specified. Traverse to Project Options->Directories->Include Directories, and add the path to the Phidget installation directory: 

C:\Program Files\Phidgets

Mac OSX

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:

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 compile, link the Phidget libraries, and build an executable binary on MacOS, do (for example, depending on the Headers location): 

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

After using gcc, you will have an executable named example that you can run.

When writing your code from scratch, you must include a reference to the library header: 

  #include <phidget21.h>

Then, you would compile your completed C/C++ code the same way as the examples.

Linux

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:

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 Linux, compile and install them as explained on the main Linux page

To compile, link the Phidget libraries, and build a binary executable on Linux, do the following in a terminal in the directory with example.c: 

  gcc example.c -o example -lphidget21

After using gcc, you will have an executable named example that you can run. On Linux, if you have not set up your udev rules for USB access you will need to run the program as root.

When writing your code from scratch, you must include a reference to the library header: 

  #include <phidget21.h>

Then, you would compile your completed C/C++ code the same way as the examples.

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 them better so you can change them.

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When changing the examples to do what you want, or writing your own code, you will probably find these API resources useful because they outline the C/C++ functions that you can use:

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Common Problems and Solutions/Workarounds

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

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