OS - Linux: Difference between revisions

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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]]
{|
|style="vertical-align:middle; width: 60%;"|
==Getting Started with Linux==
Welcome to using Phidgets with Linux!


You need kernel '''version 2.6''' or later.
If you are ready to go, the first step in creating Linux applications with Phidgets is installing our libraries.
|{{TOC limit|3}}
|}
===Install===
The first step to using Phidgets with Linux is installing the Phidget22 libraries.
{{LinuxSupport}}
If you're running one of the supported distros, we recommend using the '''Package Install'''. For other systems, you can use the '''Source Install'''.  


==Getting Started (Libraries and Drivers)==
<div class="bigTabs">
<tabber>
Package Install=
====Install Script====
To run the install script and install phidget22, enter the following command in the terminal:


Linux does not have a graphical user interface to check your Phidget, but it does have a complete API for [[#Programming Languages|many languages]].
{{LinuxInstallScript}}


For any language, you will need the basic Phidget Libraries for Linux:
====Manual Install====
To install our package repository manually, enter the following command in the terminal, replacing ''distro'' with your distro codename:


*[http://www.phidgets.com/downloads/libraries/libphidget_2.1.8.20110615.tar.gz Phidget Libraries]
{{LinuxGetKey}}


===Installing===
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.


To install the libraries, follow these steps:
Update your package lists:
{{LinuxAptUpdate}}


#Download '''libusb-0.1''' and its development libraries
Finally, install the Phidget package by entering the command below:
#*Try <code>apt-cache search libusb</code> in a terminal to find current packages
{{LinuxAptInstall}}
#*Or install [http://www.libusb.org/ from source], which includes the libusb development libraries
#Unpack and install the '''Phidget Libraries''' for Linux (download above)
#*From the main libraries directory, run:
#*:<code>./configure</code>
#*:<code>make</code>
#*:<code>sudo make install</code>
#*This will compile phidget21.h and place the library into your gcc path


'''Note:''' Although the libraries are written in C, the libraries for Python, Java, and most other Phidget-supported languages depend on them.
====Additional Packages====
You may also want to apt-get 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 Guide|'''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


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


====Software====
|-|
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-get install libusb-1.0-0-dev
</syntaxhighlight>


To confirm that the libraries were installed correctly and can be used in code, you can use the Phidget C Examples:


*[http://www.phidgets.com/downloads/examples/phidget21-c-examples_2.1.8.20111028.tar.gz Phidget C Examples]
Next, download and unpack the following files:
*[https://cdn.phidgets.com/downloads/phidget22/libraries/linux/libphidget22.tar.gz libphidget22] (Mandatory)
*[https://cdn.phidgets.com/downloads/phidget22/libraries/linux/libphidget22extra.tar.gz libphidget22extra] (Optional - needed by NetworkServer and Admin)
*[https://cdn.phidgets.com/downloads/phidget22/libraries/linux/libphidget22java.tar.gz libphidget22java] (Optional - Java Libraries)
*[https://cdn.phidgets.com/downloads/phidget22/servers/linux/phidget22networkserver.tar.gz phidget22networkserver] (Optional - [[Phidget Network Server]])
*[https://cdn.phidgets.com/downloads/phidget22/tools/linux/phidget22admin.tar.gz phidget22admin] (Optional - Phidget Admin Tool)
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.


The easiest way to confirm correct installation will be to compile and run the '''<code>HelloWorld</code>''' C example.  This does not involve writing any C code, but it does involve compiling the example and running it, which is a quick process as we show below.  If you feel more comfortable running the '''<code>HelloWorld</code>''' 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:
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.


1. Unpack the '''Phidget C Examples''' (download above)<br>
You can handle this in a number of ways:
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
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>


</source>
The libraries are now installed on your machine. Next, you should set the UDev Rules.
</font>
</tabber>
</div>
</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
=== 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:


</source>
sudo ./HelloWorld
</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 '''<code>libphidget21.a</code>''' and '''<code>libphidget21.so</code>''' in the library location (usually '''<code>/usr/lib</code>''').  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;">
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">
<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>
 
====Hardware====
 
If the out-of-the-box examples do not work, make sure the Phidget is seen by your USB interface.  To check this, 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:
 
<div style="background-color: #f3f3f3; border-color: #1c9edb; border-width:1px; border-style: dashed;">
<font size="3">
<source lang=bash>
 
    $> dmesg | tail
    ....(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 [[#Limitations | limitations section below]] 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>


If you don't see similar lines to these at the tail of your kernel log, take a look at the [[#Troubleshooting|troubleshooting]] section below, as well as the '''Communications''' section of our [[General Troubleshooting Primer#Communications Troubleshooting|general troubleshooting page]].
# 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"


====Troubleshooting====
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. 


If the examples '''do not''' work but USB '''does''' work (i.e. your computer can consistently see the device in the [[#Hardware|hardware]]), take a moment to check the basics:
===Verify===
* No other programs, drivers, or processes are using that USB port in software
The best way to verify that your libraries are working properly is to compile and run an example program.
* You are running the example program as root (or your udev rules have been set properly)
* 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 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 after the troubleshooting guide, please [[Support|ask us]]!


==Programming Languages==
First, download and unpack this C example:
*[https://cdn.phidgets.com/downloads/phidget22/examples/c/Manager/Phidget22_HelloWorld_C_Ex.zip HelloWorld C example]


Now that you have the basic libraries installed, you can pick your language and begin programming! 
'''Note:''' If using the Debian intallation methods, you will need to install the '''libphidget22-dev''' package to use the C libraries for Phidget22


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.
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>


On Linux, we recommend the following languages:


*[[Language - C/C++|C/C++]]
Run the HelloWorld example:
*[[Language - Java | Java]]
<syntaxhighlight lang=bash>
*[[Language - Python | Python]]
./HelloWorld
*[[Language - C Sharp | C#]] (Using [[Language - C Sharp#Mono|Mono]])
</syntaxhighlight>
*[[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:


*[[Language - MATLAB|MATLAB]]
Your terminal should look something like this:
[[File:linux_helloworld.PNG|link=|center]]


==Webservice==


The Phidget Webservice allows you to remotely control a Phidget over a network.<br>
The HelloWorld program will simply communicate when a Phidget has been attached or detached, as can be seen in the image above.
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
*The Webservice on Linux uses <code>avahi</code>


==Common Problems and Solutions==
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!


None yet, yay!
==Programming==
Ready to write some code? Select one of the programming languages below:


Maybe talk about udev rules?
{{Programming_Languages_Table}}


==Limitations==
==Older Versions==
If you need older versions of the Phidget22 Linux libraries, [{{SERVER}}/downloads/phidget22/libraries/linux/libphidget22/ 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.
If you need Phidget21 Linux Libraries, [{{SERVER}}/downloads/phidget21/libraries/linux/libphidget/ click here].

Latest revision as of 15:45, 9 September 2024

Getting Started with Linux

Welcome to using Phidgets with Linux!

If you are ready to go, the first step in creating Linux applications with Phidgets is installing our libraries.

Install

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

Supported Distros / Archs
Debian 6 (Squeeze) i386 armel
Debian 7 (Wheezy)
Debian 8 (Jessie) armhf
Debian 9 (Stretch)
Debian 10 (Buster) amd64 arm64
Debian 11 (Bullseye)
Debian 12 (Bookworm)
Ubuntu Xenial 16.04 LTS i386 armhf
Ubuntu Bionic 18.04 LTS amd64 arm64
Ubuntu Focal 20.04 LTS
Ubuntu Jammy 22.04 LTS
Ubuntu Noble 24.04 LTS

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

Install Script

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-get install -y libphidget22


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

Manual Install

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

wget -qO /usr/share/keyrings/phidgets.gpg \
  https://www.phidgets.com/gpgkey/pubring.gpg
echo deb [signed-by=/usr/share/keyrings/phidgets.gpg] \
  http://www.phidgets.com/debian distro main \
  > /etc/apt/sources.list.d/phidgets.list


sudo wget -qO /usr/share/keyrings/phidgets.gpg \
  https://www.phidgets.com/gpgkey/pubring.gpg
echo deb [signed-by=/usr/share/keyrings/phidgets.gpg] \
  http://www.phidgets.com/debian distro main | sudo tee \
  /etc/apt/sources.list.d/phidgets.list > /dev/null

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-get update


sudo apt-get update

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

apt-get install libphidget22


sudo apt-get install libphidget22

Additional Packages

You may also want to apt-get 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-get 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:

  1. 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:

Core Languages Mobile Languages Other Languages
C Sharp C# Objective C Objective C LabVIEW LabVIEW
C/C++ C/C++ Swift Swift Max/MSP Max/MSP
Python Python Android Android Java
Java Java
Visual Basic .NET Visual Basic .NET
JavaScript JavaScript

Older Versions

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

If you need Phidget21 Linux Libraries, click here.

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