Language - C

From Phidgets Support
Revision as of 20:12, 21 December 2011 by 192.168.3.178 (talk)

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

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Support

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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 2000 / XP / Vista / 7
  • Linux (including PhidgetSBC)
  • Mac OS X

Windows

C/C++ programs on Windows depend on three files.

  • 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.

Visual Studio


Borland

GCC on Windows


Dev C++


Run The 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 Microsoft Visual C/C++ were written Microsoft Visual Studio 2005. They also work well in other versions. The Standard C/C++ are intended for standard gcc compilers.

Specific setup for the compilers/IDEs are 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(!!!mp what does this mean!!!).

Follow The Examples

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Write Your Own Code (Windows)

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General Windows Library Setup


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 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

Create and Build Your Project

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

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:

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

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.

Follow The Examples

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Write Your Own Code (Mac OSX/Linux)

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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:


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.

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Dev C++
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

Your program will now have access to Phidgets


Manual Install

Windows
Files needed: phidget21.h, phidget21.lib, phidget21.dll These files should be linked to Library Page - file section
Place phidget21.dll into C:\WINDOWS\system32. phidget21.h and phidget21.lib can be placed anywhere as long as the path to them are specified with your compiler

Common Problems and Solutions/Workarounds

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