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<metadesc>Communicate over USB with sensors, controllers and relays with Phidgets! Program in Linux using a wide variety of programming languages.</metadesc>
[[Category:OS]]
[[Category:OS]]
__TOC__
{|
==Quick Downloads==
|style="vertical-align:middle; width: 60%;"|
Already know what you're doing? Here you go:
*[{{SERVER}}/downloads/phidget22/libraries/linux/libphidget22.tar.gz Phidget Libraries for Linux]
*[{{SERVER}}/downloads/phidget22/servers/linux/phidgetnetworkserver22.tar.gz Phidget Network Server for Linux]
*[[Software License]]
 
==Getting Started with Linux==
==Getting Started with Linux==
Welcome to using Phidgets with Linux. If you haven't already, check out the [[:Category:UserGuide|user guide]] for your device. If you are ready to go, the first step in creating Linux applications with Phidgets is installing the Phidget libraries!
Welcome to using Phidgets with Linux!  


===Installing===
If you are ready to go, the first step in creating Linux applications with Phidgets is installing our libraries.
To install the libraries, follow these steps:
|{{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'''.


#Install libusb-1.0 development libraries - {{Code|libusb-1.0-0-dev}}. 
<div class="bigTabs">
#*Note that libusb-1.0 may be already on your system, but the development libraries probably aren't.
<tabber>
#*Search for {{Code|libusb-1.0-0-dev}} or similar in your distribution package directory via {{Code|sudo apt-get install libusb-1.0-0-dev}}
Package Install=
#*Or install [http://www.libusb.org/ from source].
====Install Script====
#Unpack and install the [{{SERVER}}/downloads/libraries/libphidget22.tar.gz Phidget Libraries]
To run the install script and install phidget22, enter the following command in the terminal:
#*From the main unpacked libraries directory, run:
#*:{{Code|./configure}}
#*:{{Code|make}}
#*:{{Code|sudo make install}}
#*This will compile phidget22.h and place the library into your gcc path


'''Note:''' Although these libraries are written in C, the additional libraries for Python, Java, and most other Phidget-supported languages depend on them so they must be installed no matter what else you want to do. 
{{LinuxInstallScript}}


===Verify===
====Manual Install====
To confirm that the libraries were installed correctly and can be used in code, you can use the [{{SERVER}}/downloads/examples/phidget21-c-examples.tar.gz C examples].
To install our package repository manually, enter the following command in the terminal, replacing ''distro'' with your distro codename:


The easiest way to confirm correct installation will be to compile and run the {{Code|HelloWorld}} C example, included in the examples download.  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}} 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.
{{LinuxGetKey}}


To compile and run the basic C example for checking your installation:
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.


1. Unpack the Phidget Generic C Examples<br>
Update your package lists:
2. Open a terminal (often Ctrl-Alt-T) and go to the directory where the examples are unpacked<br>
{{LinuxAptUpdate}}
3. Compile the {{Code|HelloWorld.c}} example:<br>
<div class="source">
<syntaxhighlight lang=bash>


gcc HelloWorld.c -o HelloWorld -lphidget22
Finally, install the Phidget package by entering the command below:
{{LinuxAptInstall}}


</syntaxhighlight>
====Additional Packages====
</div>
You may also want to apt-get install the following optional packages:
4. Run the {{Code|HelloWorld}} example:<br>
* '''libphidget22-dev''': The C development libraries for Phidget22
<div class="source">
* '''libphidget22extra''': Extra runtime library required for the Network Server and Admin tools
<syntaxhighlight lang=bash>
* '''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


sudo ./HelloWorld


</syntaxhighlight>
The libraries are now installed on your machine. Next, set up the UDev rules below.
</div>
(The sudo is needed for USB access for now, see the [[#Setting udev Rules|Setting udev Rules]] section for how to change this)


The {{Code|-lphidget22}} will look in the standard library location for your Linux distribution (usually {{Code|/usr/lib/}}) for the Phidget 22 library file.  Generally, libraries to be linked on Linux through {{Code|gcc}} have a naming convention.  For example, {{Code|-lphidget22}} looks for the binary files '''{{Code|libphidget22.a}}''' and '''{{Code|libphidget22.so}}''' in the library location.  These files are automatically put in the library location during the {{Code|make install}} step of [[#Installing | installing the libraries]].
|-|
 
Source Install=
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:
====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:
<div class="source">
<syntaxhighlight lang=bash>
<syntaxhighlight lang=bash>
 
apt-get install libusb-1.0-0-dev
$ 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...
 
</syntaxhighlight>
</syntaxhighlight>
</div>
===Programming===
Ready to write some code? Select one of the programming languages below:
*[[Language - C/C++|C/C++]]
*[[Language - Java | Java]]
*[[Language - Python | Python]]
*[[Language - C Sharp | C#]]
*[[Language - Visual Basic .NET | VB.Net]]
*[[Language - JavaScript | JavaScript]]


==Phidget Network Server==


The Phidget Network Server allows you to remotely control a Phidget over a network.<br>This section helps you install, check, and use the Network Server on Linux, but we also have an overview of the [[Phidget Network Server]] in general.
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.


===Installing the Network Server===


To install the Network Server, you must first have the [[#Installing|Phidget libraries installed]]. Then, follow these steps:
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.


#Download '''avahi''' and its development libraries (mdnsresponder/bonjour is also an option, see the [[#Network Server with mDNSResponder|network server with mDNSResponder]] section)
You can handle this in a number of ways:
#*Try {{Code|apt-cache search avahi}} in a terminal to find current packages
#*Often, this is installed in a default system, you may already have it
#Unpack and install the [{{SERVER}}/downloads/libraries/phidgetnetworkserver.tar.gz Phidgets Network Server] source code tarball for Linux
#*From the unpacked Network Server source code directory, run:
#*:{{Code|./configure}}
#*:{{Code|make}}
#*:{{Code|sudo make install}}
#*This will compile the executable {{Code|phidget22networkserver}} and place it into {{Code|/usr/bin/phidget22networkserver}}


====Network Server with mDNSResponder====
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>


To use '''mdnsresponder''' instead of avahi, change the configure script to be:
The libraries are now installed on your machine. Next, you should set the UDev Rules.
 
</tabber>
<div class="source">
<syntaxhighlight lang=bash>
./configure --enable-zeroconf=bonjour
</syntaxhighlight>
</div>
</div>


(To see all options, use {{Code|./configure --help}} like you would any configure script)
=== 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:


===Setting Up the Network Server===
sudo ./HelloWorld


To set up and use the Phidget Network Server, it helps to have [[#Setting udev Rules|set your udev rules]].  Otherwise, you must run it as root.
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:


You can get command line help with {{Code|phidget22networkserver}} by using the {{Code|-h}} option:
# 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"


<div class="source">
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. 
<syntaxhighlight lang=bash>
$ phidget22networkserver -h
</syntaxhighlight>


<syntaxhighlight lang=text>
===Verify===
usage: phidget22networkserver [-D][-E][-c <cfg>][-l <logfile>][-v][-w]
The best way to verify that your libraries are working properly is to compile and run an example program.
  -D          run as daemon
  -E          log to stderr
  -c <cfg>    configuration file
  -l <logfile> log to 'logfile'
  -v          enable verbose logging (may be specified more than once)
  -p          run phidget sever
  -w          run web server
</syntaxhighlight>
</div>
 
You will see this help regardless of whether the network server was correctly hooked in to avahi.  In fact, you will see it even if you explicitly disabled mDNS in the {{Code|./configure}} step at compile:
 
<div class="source">
<syntaxhighlight lang=bash>
  ./configure --disable-zeroconf
</syntaxhighlight>
</div>
 
===Using the Network Server===
 
To use a Phidget over the network server, you'll want to:
* Obtain code you can use to open a Phidget remotely
* Start the network server on the computer that directly connects to the Phidget
* Run your program on the remote computer that will control the Phidget over the network
 
The easiest way to test these steps on Linux is simply to set up the network server and run the Phidget program on the same computer, using the loopback interface.  Later, you can replace one of the two ends with a different computer and/or operating system.


To quickly create code to run remotely, in our examples we include commented out lines with openRemote() function calls of different types.  In the C example for your device, find the line that says:


{{Code|CPhidget_open((CPhidgetHandle) device, -1)}}
First, download and unpack this C example:
*[https://cdn.phidgets.com/downloads/phidget22/examples/c/Manager/Phidget22_HelloWorld_C_Ex.zip HelloWorld C example]


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


<div class="source">
Next, open the terminal at the example location. Compile the example by entering the following command:
<syntaxhighlight lang=bash>
<syntaxhighlight lang=bash>
  int serial_number = 37299
  gcc HelloWorld.c -o HelloWorld -lphidget22
CPhidget_openRemoteIP ((CPhidgetHandle) device, serial_number, "127.0.0.1", 5001, NULL)
</syntaxhighlight>
</syntaxhighlight>
</div>


Except that you should replace '''37299''' with the serial number of your Phidget, which you can obtain from either the Phidget board itself, or from when you [[#Checking|ran the HelloWorld example code]].  The IP address "127.0.0.1" simply loops back to the same computer, and 5001 is the default port as found from using {{Code|phidget21networkserver -h}} in [[#Setting Up the Network Server|the Setting Up the Network Server]] section.  The NULL is used to not specify a password.


Save the changed example under a different filename.  In the walkthrough here, we are using the {{Code|InterfaceKit.c}} example, and we rename it to be {{Code|InterfaceKitRemote.c}}
Run the HelloWorld example:
 
Compile your new C file. In our {{Code|InterfaceKitRemote.c}} case, this would be by:
 
<div class="source">
<syntaxhighlight lang=bash>
<syntaxhighlight lang=bash>
gcc InterfaceKitRemote.c -o InterfaceKitRemote -lphidget21
./HelloWorld
</syntaxhighlight>
</syntaxhighlight>
</div>


1. Start two terminals to run this test, usually opened via Ctrl-Alt-T.  Your [[#Setting udev Rules|udev rules]] need to be set up or you should use sudo for every command.  First, start the network server in Terminal #1:


[[Image:Linux_ws_start.png|link=]]
Your terminal should look something like this:
[[File:linux_helloworld.PNG|link=|center]]


This will broadcast any Phidget events, and receive any Phidget requests, both over the network.


2. Start the InterfaceKitRemote program that you just compiled which will open the remote Phidget. In this case, it is {{Code|InterfaceKitRemote}}:
The HelloWorld program will simply communicate when a Phidget has been attached or detached, as can be seen in the image above.


[[Image:Linux_ws_step2.png|link=]]


3. Now, plug in the Phidget! The {{Code|phidget21networkserver}} program captures the attach and other events and sends them out over the network (in the background in Terminal #1) and the Phidget software objected opened with openRemote in Terminal #2 receives them:
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!


[[Image:Linux_ws_step3.png|link=]]
==Programming==
 
Ready to write some code? Select one of the programming languages below:
4. You can confirm that the network server was indeed behind this exchange by killing the network server process while still allowing the remote program to run:
 
[[Image:Linux_ws_step4.png|link=]]
 
===Debugging the Network Server===
 
In addition to enabling [[General Phidget Programming#Logging|logging]] in your Phidget code, you can get additional debugging information from the Network Server itself.  You can enable logging by editing {{Code|networkserver.cfg}}, which can be found in the build directory for the network server.
 
<div class="source">
<syntaxhighlight lang=bash>
 
# Server log level
# verbose | debug | info | warn | err
loglevel: debug
 
# Server log file
logfile: "/home/<username>/Desktop/networkserver.log"
</syntaxhighlight>
</div>
 
You can change the {{Code|loglevel}} to change what kind of messages show up in the logfile. Each successive level contains the messages of the lower levels as well.
 
* '''err''': The lowest logging level; Only messages from errors will be logged.
* '''warn''': Adds warning messages which result from unexpected but not necessarily erroneous behaviour.
* '''info''': Adds informational messages that track important events in the network server.
*'''debug''': For debugging the inner workings of the network server; not typically useful for end-users.
*'''verbose''': The highest logging level; Even not-very-important events will be tracked, so it may be difficult to find the messages that matter.
 
The {{Code|logfile}} path will lead you to the log file, or you can change the path to something else.
 
If you suspect multicast DNS (mDNS) may be the problem, you can:
* Try compiling the network server with mDNSResponder, as described in [[#Installing the Network Server|Installing the Network Server]], or
* Try compiling the network server completely without mDNS, as described in [[#Setting Up the Network Server|Setting Up the Network Server]]
 
==Advanced Information==
 
===Setting udev Rules===
 
If you don't want to be using {{Code|sudo}} to run Phidget programs (including the Network Server) forever, you will want to create a {{Code|udev}} rule to allow yourself access to the Phidget when you are not root.
 
Udev has an easy way to set the owner and permissions of the USB interface of the Phidget - it finds all devices that match a given set of rules, and applies new traits to them.  But you need to give udev something to match in order to apply the new settings.  Here, we will tell udev to match the vendor code for Phidgets, Inc. 
 
We recommend that you use the rules file included in the library download you have already installed.  Check the README file included in that download for information on how exactly to install it, or continue reading here. 
 
The rules for udev are kept in files in {{Code|/etc/udev/rules.d/}} and are traditionally grouped into order of running (10 runs before 20, 30, etc) and device type (cd, network, etc).  There should be one or more files in there already. Simply find the file named {{Code|99-libphidget22.rules}} included with our library files, and move it into {{Code|/etc/udev/rules.d/}}.
 
Strictly speaking, the files run in lexical order (i.e. the order they're listed when you use {{Code|ls}}).  A device can match many rules, and all will apply (if possible).  If conflicting rules are found, the first rule found is followed.
 
===Starting the Network Server at Boot===
 
If you are tired of starting the network server on the command line all the time, you can have the network server start when your system starts, every time.
 
====User Space====
 
If you are running a standard Linux machine with an X-server (Unity, KDE) the easiest way to do this is to have the Phidget Network Server start when your x server starts.
 
In this case, the network server will be running in user space, so your [[#Setting udev Rules|udev rules need to be set up]] for the your user permissions to be able to access the USB ports using libusb.
 
Within the X-windowing system, there is usually some sort of {{Code|System &rarr; Settings/Preferences &rarr; Startup}} that you can choose to add programs that start when a user session starts.  On Ubuntu you can use Unity to find programs listing "startup" in their names to accomplish the same thing.  This will eventually lead you to a window like this one:
 
[[Image:linux_ws_boot.png|400px|link=]]
 
Simply add the {{Code|/usr/bin/phidget22networkserver}} program to the list.
 
====As A Service====
 
You would want to set the boot start of {{Code|phidgetnetworkserver21}} to be a service if you are running a server, or a headless machine.  It is handy any time you need the network server to be started as a booted, respawning service with a presence in different run levels and for all users.
 
A service is essentially a program that hangs out in the background, waiting to be used by some incoming task.  When the service is needed, the service forks a program to handle that need.  Most services that run on your Linux computer already have the ability to fork themselves. 
 
The network server, however, is just a binary on Linux - {{Code|phidgetnetworkserver21}} - and so we need a program that handles the forking for us.  For this, we use the {{Code|start-stop-daemon}} program to spawn a standalone process for us, or kill it, based on our service-like start, stop, and restart commands.
 
To do this, we need:
# A script that tells the boot process how to start and handle the networkserver (i.e. by using {{Code|start-stop-daemon}})
# A link from that script to the boot list
# An initialization file for the script
 
First, the script.  We will walk through Debian here, both because it is such a common distribution and because it is the distribution that our [{{SERVER}}products.php?product_id=1073 Single Board Computer] runs.  But {{Code|init}} is surprisingly diverse on Linux, including everything from a different boot order, to different initialization programs and structure, and even different runlevels. 
 
On Debian (including Ubuntu), the initialization script covers:
* Runlevels that the service should be present on
* Dependencies of the service
* Name of the service and other informative data
* The location of the PIDFILE, which stores the process ID (pid) for later dealing with a spawned instance
* Any configuration file locations
* What to do when the service is given instructions to '''start''', '''stop''', or '''reload'''.
 
The Debian script we use to start the network server on the [{{SERVER}}products.php?product_id=1073 Single Board Computer]:
 
<div class="source">
<syntaxhighlight line start="1" lang=bash>
 
#!/bin/sh
 
### BEGIN INIT INFO
# Provides:          phidgetnetworkserver
# Required-Start:    $network $remote_fs
# Required-Stop:    $network $remote_fs
# Should-Start:      avahi
# Should-Stop:      avahi
# Default-Start:    2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: Phidget Network Server
# Description:      Phidget Network Server for controlling Phidgets over the network.
### END INIT INFO
 
DESC="Phidget Network Server"
NAME=phidgetnetworkserver
BIN=phidgetnetworkserver21
DAEMON=/usr/bin/$BIN
PIDFILE=/var/run/$NAME.pid
CFG=/etc/default/$NAME
 
# Gracefully exit if the package has been removed.
test -x $DAEMON || exit 0
 
# load config
pws_port="5001"
pws_serverid=""
pws_password=""
[ -f $CFG ] && . $CFG
 
start() {
[ -z "$pws_port" ] || OPTIONS="-p $pws_port "
[ -z "$pws_password" ] || OPTIONS="$OPTIONS-P $pws_password "
 
if [ -z "$pws_serverid" ]; then
OPTIONS="$OPTIONS -n $( hostname )"
else
OPTIONS="$OPTIONS -n $pws_serverid"
fi
echo -n "Starting $DESC: "
start-stop-daemon -S -b -q -p $PIDFILE -m -x $DAEMON -- $OPTIONS && echo "OK" || echo "ALREADY RUNNING"
}
 
stop() {
echo -n "Stopping $DESC: "
start-stop-daemon -K -q -p $PIDFILE -x $DAEMON && echo "OK" || echo "NOT RUNNING"
}
 
case "$1" in
  start)
start
;;
  stop)
stop
;;
  restart|force-reload)
stop
sleep 1
start
;;
  *)
echo "Usage: $0 {start|stop|restart}"
esac
 
exit 0
</syntaxhighlight>
</div>
 
 
Save the script into a file called {{Code|phidgetnetworkserver}}, and use {{Code|chmod 755}} to make it executable.
 
Also on Debian, startup service scripts should go in {{Code|/etc/init.d}}, and then put within the appropriate runlevel-numbered folder - by symbolic link.  There is a handy tool to do this for you, called {{Code|insserv}}:
 
<div class="source">
<syntaxhighlight lang=bash>
sudo insserv -d phidgetnetworkserver
</syntaxhighlight>
</div>
 
 
The {{Code|insserv}} program is the program that makes use of the {{Code|### BEGIN INIT INFO...### END INIT INFO}} that appears at the top of the {{Code|phidgetnetworkserver}} script.  Use {{Code|man insserv}} for more information.  The {{Code|insserv}} tool handles the mess of finding the right runlevel folders (i.e. the {{Code|rc.d}} numbered folders) and making the appropriate links. You can see what links would be updated by running {{Code|insserv}} with the {{Code|-n}} option, for a dry run.
 
'''Note:''' When you run {{Code|insserv}}, all of the dependencies for the boot order are re-written.  This means that all of the initialization scripts in {{Code|/etc/init.d}} are re-examined.  So, you'll probably get a lot of output when you run the command.
 
Then, you can check that {{Code|phidgetnetworkserver}} is on the service list with:
 
<div class="source">
<syntaxhighlight lang=bash>
service --status-all
</syntaxhighlight>
</div>
 
 
And you can start it right now without rebooting like this:
 
[[Image:linux_system_service_start.png|link=]]
 
The {{Code|service}} command has many options to start and stop services like the phidgetnetworkserver, try {{Code|man service}} for more information.
 
At this point, you can follow the client instructions on [[#Using the Network Server|using the network server]] to create a loopback test for the new network server that should now be running.
 
The final piece, for future configuration changes, is that the {{Code|/etc/init.d}} script looks for the file {{Code|/etc/default/phidgetnetwork server}} upon starting up.  The file is expected to contain the port, server ID, and password for the server side of the network server.  These are also set in the {{Code|phidgetnetworkserver}} script in {{Code|init.d}}, as you can see from reading the code above, but if you want to change them a lot, you can edit the configuration file rather than changing the {{Code|phidgetnetworkserver}} script and re-installing by {{Code|insserv}} every time.  The configuration file in {{Code|/etc/default/}} should contain the same syntax as that used in the script source above:
 
<div class="source">
<syntaxhighlight lang=bash>
pws_port="5001"
pws_serverid=""
pws_password=""
</syntaxhighlight>
</div>
 
===Cross-Compiling with a Custom Toolchain===
 
This would allow you to have the Phidget libraries compiled to include in code for an embedded device.  When developing for an embedded device, you will often write code for it on your 'normal' computer, and then build the code to binary with a different target than the processor in your computer.  Many microcontrollers do not have the ability to run a full operating system, and hence cannot compile code natively. 
 
The collection of tools used to create binary code for a separate system is called a ''toolchain''.  Compiling the Phidget libraries specifically for an embedded system, and placing them into the path for writing code on top of the libraries is like adding another link in this chain.
 
You can use the typical {{Code|./configure}} setup for custom build targets:
 
<div class="source">
<syntaxhighlight lang=bash>
./configure --prefix=toolchain_location --build=this_system --host=target_system
</syntaxhighlight>
</div>
 
For the Phidget libraries, the {{Code|./configure}} tool works this way as well. You'd use this in the [[#Installing|install the libraries section]] setup. For example, let's say you're building the libraries to develop code for the [{{SERVER}}products.php?product_id=1073 Single Board Computer] as a target.  Your system is a standard Linux system (i686-pc-linux-gnu) and the target system for the SBC is {{Code|arm-linux-gnueabi}}.  For this target, you'll need the base of the GNU embedded Debian chain:
 
<div class="source">
<syntaxhighlight lang=bash>
sudo apt-get install gcc-arm-linux-gnueabi
</syntaxhighlight>
</div>
 
Then, download the Phidget libraries [[#Quick Downloads|above]] and unpack them into a folder {{Code|phidget_libraries}}.  If {{Code|/usr/arm-linux-gnueabi}} is the location of your ARM toolchain (downloaded above in {{Code|gcc-arm-linux-gnueabi}}), type:
 
<div class="source">
<syntaxhighlight lang=bash>
~/phidget_libraries $> ./configure --prefix=/usr/arm-linux-gnueabi --build=i686-pc-linux-gnu --host=arm-linux-gnueabi
</syntaxhighlight>
</div>
 
===Linux on Non-Standard Systems===
 
We occasionally get requests to use Phidgets on Linux systems other than a standard laptop or desktop.  One example is the Raspberry Pi system.  Often these systems include USB ports, so the combination makes sense.


Our libraries are installed by building from source, and their main dependency is the {{Code|libusb-1.0-0-dev}} library, so if you can get gcc on your machine (or set up a cross compiler for it) and you can also install the libusb-1.0 development headers, you can probably get Phidgets to work.  Of course, we don't offer much support for these systems, so - depending on your system - expect to spend some raw time getting it up and going. 
{{Programming_Languages_Table}}


If you're new to the embedded computer thing, keep in mind that for these super basic systems, once you've gotten a power supply, and storage, and put the kernel you want on it, and then spent a couple of days of time getting things working, and  more time getting your drivers going, costs add up pretty quickly.  If you want a compact system that works right out of the box (and which can use all of our analog sensors in addition to our USB Phidgets), check out our [{{SERVER}}products.php?product_id=1073 Single Board Computer].  Our SBC3:
==Older Versions==
* Has many more USB ports than super-stripped devices, and also has digital and analog ports
If you need older versions of the Phidget22 Linux libraries, [{{SERVER}}/downloads/phidget22/libraries/linux/libphidget22/ click here].
* Includes a power supply and can run on batteries easily
* Has a nice amount of RAM, a decent embedded processor, and built-in onboard storage (we've run R, GRASS, and X11 on it)
* Includes installed Debian, working Phidget drivers, and [[Phidget Network Server|networked Phidget drivers]] from the moment it ships
* Has access to the full Debian repository including Python, Mono .NET, Ruby, and gcc
* Has a kernel development kit with patch file and instructions for adding new drivers (bluetooth, wireless, and so on)
* Comes with very in-depth documentation and technical support by phone and email
* Etc, etc.
The [[Phidget Network Server|networked support]] in particular allows it to work with your cell phone and more.


But if you really do want a raw hobbyist system to tinker with, go for it!  We're all nerds here - we've been there too and we certainly understand!
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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