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Phidgets can run on Linux directly using USB, or remotely over a network using the [[Phidget Webservice]]
<metadesc>Communicate over USB with sensors, controllers and relays with Phidgets! Program in Linux using a wide variety of programming languages.</metadesc>
[[Category:OS]]


You need kernel '''version 2.6''' or later.
==Getting Started with Linux==
Welcome to using Phidgets with Linux!


==Getting Started (Libraries and Drivers)==
===Install===
The first step to using Phidgets with Linux is installing the Phidget22 libraries.


Linux does not have a graphical user interface to check your Phidget, but it does have a complete API for many languages.
We provide prebuilt packages for Debian, Ubuntu, and their derivatives.


For any language, you will need the basic Phidget Libraries for Linux:
If you're running a supported distros, we recommend using the '''Package Install'''. For other systems, you can use the '''Source Install'''.


*[http://www.phidgets.com/downloads/libraries/libphidget_2.1.8.20110615.tar.gz Phidget Libraries]
<div class="bigTabs">
<tabber>
|-|Package Install=
{{LinuxPackageInstall}}


===Installing===
|-|Source Install=
====Source Install====
To install our libraries, first install libusb-1.0 development libraries. The exact command and package name will vary depending on distribution. For Debian based distributions, including Ubuntu and Mint, the command would be:
<syntaxhighlight lang=bash>
apt install libusb-1.0-0-dev
</syntaxhighlight>


To install the libraries, follow these steps:


#Download '''libusb-0.1''' and its development libraries
Next, download and unpack the following files:
#*Try <code>apt-cache search libusb</code> in a terminal to find current packages
*[https://cdn.phidgets.com/downloads/phidget22/libraries/linux/libphidget22.tar.gz libphidget22] (Mandatory)
#*Or install [http://www.libusb.org/ from source], which includes the libusb development libraries
*[https://cdn.phidgets.com/downloads/phidget22/libraries/linux/libphidget22extra.tar.gz libphidget22extra] (Optional - needed by NetworkServer and Admin)
#Unpack and install the '''Phidget Libraries''' for Linux (download above)
*[https://cdn.phidgets.com/downloads/phidget22/libraries/linux/libphidget22java.tar.gz libphidget22java] (Optional - Java Libraries)
#*From the main libraries directory, run:
*[https://cdn.phidgets.com/downloads/phidget22/servers/linux/phidget22networkserver.tar.gz phidget22networkserver] (Optional - [[Phidget Network Server]])
#*:<code>./configure</code>
*[https://cdn.phidgets.com/downloads/phidget22/tools/linux/phidget22admin.tar.gz phidget22admin] (Optional - Phidget Admin Tool)
#*:<code>make</code>
Open the README file that is included at the top of each directory. This file will give you important information about how to properly install the files.
#*:<code>sudo make install</code>
#*This will compile phidget21.h and place the library into your gcc path


===Checking===


To confirm the libraries were installed and work correctly, you can check both the hardware and software sides of the interface.  It is worth checking the software side first, because if it works then you know the hardware side is also okay.
Libraries are installed in /usr/local/lib by default. If you run into trouble finding the libraries during linking or at runtime, this probably means that /usr/local/lib is not on the library path for your distribution.


====Software====
You can handle this in a number of ways:


To confirm that the libraries were installed correctly and can be used in code, you can use the Phidget C Examples:
Specify a different install folder during compile
<syntaxhighlight lang=bash>./configure --prefix=/usr && make && sudo make install</syntaxhighlight>
OR Add /usr/local/lib to the system-wide library path
<syntaxhighlight lang=bash>echo /usr/local/lib >> /etc/ld.so.conf && sudo ldconfig</syntaxhighlight>
OR Add /usr/local/lib in your local shell every time
<syntaxhighlight lang=bash>export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib</syntaxhighlight>


*[http://www.phidgets.com/downloads/examples/phidget21-c-examples_2.1.8.20111028.tar.gz Phidget C Examples]
The libraries are now installed on your machine. Next, you should set the UDev Rules.
 
</tabber>
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 library installation and not necessarily with your language.
 
To compile and run the basic C example for checking your installation:
 
1. Unpack the '''Phidget C Examples''' (download above)<br>
2. Open a terminal (often Ctrl-Alt-T) and go to the directory where the examples are unpacked<br>
3. Compile the <code>HelloWorld.c</code> example:<br>
<div style="background-color: #f3f3f3; border-color: #1c9edb; border-width:1px; border-style: dashed;">
<font size="3">
<source lang=bash>
 
    gcc HelloWorld.c -o HelloWorld -lphidget21
 
</source>
</font>
</div>
4. Run the <code>HelloWorld</code> example:<br>
<div style="background-color: #f3f3f3; border-color: #1c9edb; border-width:1px; border-style: dashed;">
<font size="3">
<source lang=bash>
 
    sudo ./HelloWorld
 
</source>
</font>
</div>
:(The sudo is needed for USB access for now)
 
The <code>-lphidget21</code> will look in the standard library location for your Linux distribution (usually <code>/usr/lib/</code>) for the Phidget 21 library file.
 
Generally, libraries to be linked on Linux through <code>gcc</code> have a naming convention.  For example, <code>-lphidget21</code> looks for the binary files libphidget21.a and libphidget21.so in the library location.  These files are automatically put in the library location during the <code>make install</code> step of [[#Installing | installing the libraries above]].
 
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:
 
<div style="background-color: #f3f3f3; border-color: #1c9edb; border-width:1px; border-style: dashed;">
<font size="3">
<source lang=bash>
 
  $ 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...
 
</source>
</font>
</div>
</div>


====Hardware====
=== Setting UDev Rules ===
By default, Linux will not grant permission to regular users to access physical hardware as a security feature.  This means that in order to run Phidgets code from user space you must grant yourself root privileges via sudo.  For example:


If the out-of-the-box examples do not work, make sure the Phidget is seen by your USB interface. You can use the kernel log reader '''<code>dmesg</code>'''.  Pipe the output of '''<code>dmesg</code>''' into the utility '''<code>tail</code>''' to simply read the last ten lines of the log:
sudo ./HelloWorld


<div style="background-color: #f3f3f3; border-color: #1c9edb; border-width:1px; border-style: dashed;">
You can grant access manually or, more commonly, set up a rules file to do it automatically keying off of the vendor code for Phidget USB devices.  To do this, create a text file called "99-libphidget22.rules" with the following contents:
<font size="3">
<syntaxhighlight lang=bash>
<source lang=bash>
# All current and future Phidgets - Vendor = 0x06c2, Product = 0x0030 - 0x00af
SUBSYSTEMS=="usb", ACTION=="add", ATTRS{idVendor}=="06c2", ATTRS{idProduct}=="00[3-a][0-f]", MODE="666"
</syntaxhighlight>


    $> dmesg | tail
Where mode 666 means every user has permission to read and write to the specified file/device. You need to then move this file to "/etc/udev/rules.d"Now you can run Phidget related code as a regular user without the OS denying permission.
    ....(9 lines)....
    [24344.013638] usb 2-1.2: new low speed USB device number 5 using ehci_hcd
 
</source>
</font>
</div>
 
The number between the [] is the system time in seconds since the last boot up, so you can tell whether the event was recent or not(This will also tell you the interrupt type of Phidget that is registered by the USB interface, see the [[OS - Linux#Limitations | Linux page limitations section]] for more information on what this means.)
 
The Phidget should both connect and disconnect properly, so unplugging it should result in an additional line at the tail:
 
<div style="background-color: #f3f3f3; border-color: #1c9edb; border-width:1px; border-style: dashed;">
<font size="3">
<source lang=bash>
 
    $> dmesg | tail
    ....(8 lines)....
    [24344.013638] usb 2-1.2: new low speed USB device number 5 using ehci_hcd
    [25094.809328] usb 2-1.2: USB disconnect, device number 5
 
</source>
</font>
</div>


====Troubleshooting====
===Verify===
The best way to verify that your libraries are working properly is to compile and run an example program.


If the examples do not work but USB can consistently see the device, take a moment to check the basics:
* You are using libusb 0.1 (not 1.0 or later)
* You have compiled versions of libphidget21.a and libphidget21.so in your system library location (usually <code>/usr/lib</code>)
* The Phidget libraries are the latest version (visit the [[#Getting Started (Libraries and Drivers)| getting started section above]] to re-download them)
* Your Linux kernel version is 2.6 or later (type '''<code>uname -r</code>''' in a terminal to get your kernel version)
* Check the [[#Limitations|limitations]] section below, some specific combinations can cause problems


If your problem doesn't seem to be fixed by the steps above, make sure that the Phidget is seen '''consistently''' by USB (if it is erratic, try our [[General Troubleshooting|general troubleshooting guide]]).  If you are still having problems, feel
First, download and unpack this C example:
*[https://cdn.phidgets.com/downloads/phidget22/examples/c/Manager/Phidget22_HelloWorld_C_Ex.zip HelloWorld C example]


==Programming Languages==
'''Note:''' If using the Debian intallation methods, you will need to install the '''libphidget22-dev''' package to use the C libraries for Phidget22


Now that you have the basic libraries installed, you can pick your language and begin programming!  
Next, open the terminal at the example location. Compile the example by entering the following command:
<syntaxhighlight lang=bash>
  gcc HelloWorld.c -o HelloWorld -lphidget22
</syntaxhighlight>


If you are not using the [[#Webservice | 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:
Run the HelloWorld example:
<syntaxhighlight lang=bash>
./HelloWorld
</syntaxhighlight>


*[[Language - C/C++|C/C++]]
*[[Language - Java | Java]]
*[[Language - Python | Python]]
*[[Language - C Sharp | C#]] (Using [[Language - C Sharp#Mono|Mono]])
*[[Language - Flash AS3 | Flash AS3]]


You can also use these languages, but they do not support [[General Phidget Programming#Event Driven Code | event driven code]], and must use [[General Phidget Programming#Logic Code | logic code]] only:
Your terminal should look something like this:
[[File:linux_helloworld.PNG|link=|center]]


*[[Language - MATLAB|MATLAB]]


==Webservice==
The HelloWorld program will simply communicate when a Phidget has been attached or detached, as can be seen in the image above.


The Phidget Webservice allows you to remotely control a Phidget over a network.<br>
Before using these webservice drivers, it may help to learn about how the [[Phidget Webservice]] works.


*[http://www.phidgets.com/downloads/libraries/phidgetwebservice_2.1.8.20111028.tar.gz Linux Phidgets Webservice] libraries
Your Phidget is now able to communicate with your development machine. The next step is selecting a programming language so you can start to write some code!
*The Webservice on Linux uses <code>avahi</code>


==Common Problems and Solutions==
==Programming==
Ready to write some code? Select one of the programming languages below:


None yet, yay!
{{Programming_Languages_Table}}


Maybe talk about udev rules?
==Older Versions==
If you need older versions of the Phidget22 Linux libraries, [{{SERVER}}/downloads/phidget22/libraries/linux/libphidget22/ click here].


==Limitations==
If you need Phidget21 Linux Libraries, [{{SERVER}}/downloads/phidget21/libraries/linux/libphidget/ click here].


* Linux will only schedule one low-speed interrupt transfer per millisecond.  The practical consequence of this is if your system has many low speed Phidgets attached, they will each be throttled down.  Low speed Phidgets require an interrupt transfer as often as every 8 milliseconds.  A Linux system could only have up to 8 of these Phidgets attached.
==Software License==
By downloading Linux Source you agree to adhere to the terms of the [https://opensource.org/licenses/BSD-3-Clause The 3-Clause BSD License].

Latest revision as of 18:28, 20 January 2025


Getting Started with Linux

Welcome to using Phidgets with Linux!

Install

The first step to using Phidgets with Linux is installing the Phidget22 libraries.

We provide prebuilt packages for Debian, Ubuntu, and their derivatives.

If you're running a supported distros, we recommend using the Package Install. For other systems, you can use the Source Install.

We recommend installing with our Install Script. If you prefer not to run a script, or the script cannot detect your distro, use the Manual Install.

To run the install script and install phidget22, enter the following command in the terminal:

curl -fsSL https://www.phidgets.com/downloads/setup_linux | bash -
apt install -y libphidget22

curl -fsSL https://www.phidgets.com/downloads/setup_linux | sudo -E bash -
sudo apt install -y libphidget22

If the curl command is not found: apt install curl and try again.

To install our package repository manually, enter the following command in the terminal, replacing distro with your distro codename:

We support Debian releases from 6 to current, and Ubuntu LTS releases from 14.04 to current. If you are using another flavour of Linux (such as Mint), which is based on Ubuntu or Debian, use the corresponding Ubuntu or Debian codename.

Update your package lists:

apt update

sudo apt update

Finally, install the Phidget package by entering the command below:

apt install libphidget22

sudo apt install libphidget22

Additional Packages

You may also want to apt install the following optional packages:

  • libphidget22-dev: The C development libraries for Phidget22
  • libphidget22extra: Extra runtime library required for the Network Server and Admin tools
  • phidget22networkserver: The Phidget Network Server, which enables use of Phidgets over your network
  • libphidget22java: The Java libraries for Phidget22
  • phidget22admin: An administrator utility for listing Phidgets and upgrading firmware
  • phidget22wwwjs: The JavaScript libraries for Phidget22. This package also installs the HTML examples which can be accessed through the web interface


The libraries are now installed on your machine. Next, set up the UDev rules below.

Source Install

To install our libraries, first install libusb-1.0 development libraries. The exact command and package name will vary depending on distribution. For Debian based distributions, including Ubuntu and Mint, the command would be:

apt install libusb-1.0-0-dev


Next, download and unpack the following files:

Open the README file that is included at the top of each directory. This file will give you important information about how to properly install the files.


Libraries are installed in /usr/local/lib by default. If you run into trouble finding the libraries during linking or at runtime, this probably means that /usr/local/lib is not on the library path for your distribution.

You can handle this in a number of ways:

Specify a different install folder during compile

./configure --prefix=/usr && make && sudo make install

OR Add /usr/local/lib to the system-wide library path

echo /usr/local/lib >> /etc/ld.so.conf && sudo ldconfig

OR Add /usr/local/lib in your local shell every time

export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib

The libraries are now installed on your machine. Next, you should set the UDev Rules.

Setting UDev Rules

By default, Linux will not grant permission to regular users to access physical hardware as a security feature. This means that in order to run Phidgets code from user space you must grant yourself root privileges via sudo. For example:

sudo ./HelloWorld

You can grant access manually or, more commonly, set up a rules file to do it automatically keying off of the vendor code for Phidget USB devices. To do this, create a text file called "99-libphidget22.rules" with the following contents:

# All current and future Phidgets - Vendor = 0x06c2, Product = 0x0030 - 0x00af
SUBSYSTEMS=="usb", ACTION=="add", ATTRS{idVendor}=="06c2", ATTRS{idProduct}=="00[3-a][0-f]", MODE="666"

Where mode 666 means every user has permission to read and write to the specified file/device. You need to then move this file to "/etc/udev/rules.d". Now you can run Phidget related code as a regular user without the OS denying permission.

Verify

The best way to verify that your libraries are working properly is to compile and run an example program.


First, download and unpack this C example:

Note: If using the Debian intallation methods, you will need to install the libphidget22-dev package to use the C libraries for Phidget22

Next, open the terminal at the example location. Compile the example by entering the following command:

 gcc HelloWorld.c -o HelloWorld -lphidget22


Run the HelloWorld example:

./HelloWorld


Your terminal should look something like this:

Linux helloworld.PNG


The HelloWorld program will simply communicate when a Phidget has been attached or detached, as can be seen in the image above.


Your Phidget is now able to communicate with your development machine. The next step is selecting a programming language so you can start to write some code!

Programming

Ready to write some code? Select one of the programming languages below:

Older Versions

If you need older versions of the Phidget22 Linux libraries, click here.

If you need Phidget21 Linux Libraries, click here.

Software License

By downloading Linux Source you agree to adhere to the terms of the The 3-Clause BSD License.