Notice: This page contains information for the legacy Phidget21 Library. Phidget21 is out of support. Bugfixes may be considered on a case by case basis. Phidget21 does not support VINT Phidgets, or new USB Phidgets released after 2020. We maintain a selection of legacy devices for sale that are supported in Phidget21. We recommend that new projects be developed against the Phidget22 Library.
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OS - Linux: Difference between revisions
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Although the libraries are written in C, the libraries for Python, Java, and most other Phidget-supported languages depend on them. | Although the libraries are written in C, the libraries for Python, Java, and most other Phidget-supported languages depend on them. | ||
The easiest way to confirm that the libraries got compiled correctly and installed in the right place will be to compile and run the HelloWorld C example. This does not involve writing any C code, but | The easiest way to confirm that the libraries got compiled correctly and installed in the right place will be to compile and run the HelloWorld C example. This does not involve writing any C code, but it does involve compiling the example and running it, as we show below. If you feel more comfortable running the HelloWorld example for your specific language, you can skip below and pick your language, but keep in mind that any problems could be with the C libraries and not necessarily with your language. | ||
If you feel more comfortable running the HelloWorld example for your specific language, you can skip below and pick your language, but keep in mind that any problems could be with the C libraries and not necessarily with your language. | |||
To compile and run the basic C example for checking your installation, copy and run these lines in a terminal, in the directory where you saved and unpacked the C examples: | To compile and run the basic C example for checking your installation, copy and run these lines in a terminal, in the directory where you saved and unpacked the C examples: |
Revision as of 20:05, 8 December 2011
Phidgets can run on Linux directly using USB, or remotely over a network using the Phidget Webservice.
You need kernel version 2.6 or later.
Getting Started (Libraries and Drivers)
Linux does not have a graphical user interface to check your Phidget, but it does have a complete API for many languages.
For any language, you will need the basic Phidget Libraries for Linux:
Installing
To install the libraries, follow these steps:
- Download libusb-0.1 and its development libraries
- Try
apt-cache search libusb
in a terminal to find current packages - Or install from source, which includes the libusb development libraries
- Try
- Unpack and install the Phidget Libraries for Linux (download above)
- From the main libraries directory, run:
./configure
make
sudo make install
- This will compile phidget21.h and place the library into your gcc path
- From the main libraries directory, run:
Checking
To confirm that the libraries were installed correctly, you can use the Phidget C Examples:
Although the libraries are written in C, the libraries for Python, Java, and most other Phidget-supported languages depend on them.
The easiest way to confirm that the libraries got compiled correctly and installed in the right place will be to compile and run the HelloWorld C example. This does not involve writing any C code, but it does involve compiling the example and running it, as we show below. If you feel more comfortable running the HelloWorld example for your specific language, you can skip below and pick your language, but keep in mind that any problems could be with the C libraries and not necessarily with your language.
To compile and run the basic C example for checking your installation, copy and run these lines in a terminal, in the directory where you saved and unpacked the C examples:
- Unpack the Phidget C Examples (download above)
- Compile and run the
HelloWorld.c
example:
gcc HelloWorld.c -o HelloWorld -lphidget21
sudo ./HelloWorld
- (The sudo is needed for USB access for now)
The -lphidget21
will look in the standard library location for your Linux distribution (usually /usr/lib/
) for the Phidget 21 library file. Generally, libraries to be linked on Linux through gcc
have a naming convention. For example, -lphidget21
looks for the libphidget21.a and libphidget21.so in the library location.
The HelloWorld program will simply print out basic information for any device you plug in, and print a message upon unplugging the device. For example, starting the program, plugging in an Interface Kit Phidget, unplugging the Interface Kit, and pressing Enter displays:
$ sudo ./HelloWorld
Opening...
Press Enter to end
Hello to Device Phidget InterfaceKit 8/8/8, Serial Number: 37299
Goodbye Device Phidget InterfaceKit 8/8/8, Serial Number: 37299
Closing...
Programming Languages
Now that you have the basic libraries installed, you can pick your language and begin programming!
If you are not using the webservice (discussed below) to control a Phidget over a network, your next step will be to delve into the use of your specific language. Each page has its own set of specific libraries, code examples, and setup instructions.
On Linux, we recommend the following languages:
You can also use these languages, but they do not support event driven code, and must use logic code only:
Webservice
The Phidget Webservice allows you to remotely control a Phidget over a network.
Before using these webservice drivers, it may help to learn about how the Phidget Webservice works.
- Linux Phidgets Webservice libraries
- The Webservice on Linux uses
avahi
Common Problems and Solutions
None yet, yay!
Maybe talk about udev rules?