Orthanc Raspberry Pi

Last update : March 20, 2016

This contribution explains how to implement an Orthanc DICOM PACS Server on a Raspberry Pi (RPI) standalone single-board computer. The Orthanc source code was compiled on a Raspberry Pi 1 model B computer and tested on RPI models B Pi 1, Pi 2 and Pi 3. I use Raspbian Jessie for my RPI’s, a free operating system based on Debian, optimized for the Raspberry Pi hardware. I call the resulting mini PACS server an OrthancPi.


Raspberry Pi genealogy

Debian Med

An Orthanc package for Debian is available at the Debian website. This package is part of Debian Med, a specific flavour of Debian that is particularly well fit for the requirements for medical practice and biomedical research. The Debian Med package is maintained by the developer of Orthanc, Sébastien Jodogne, a Medical Imaging Engineer at the Medical Physics Department from the University Hospital of Liège (CHU) in Belgium.

The stable Orthanc version for Debian Jessie is 0.8.4. The Orthanc version 1.0 is only available for the testing (Stretch) and for the unstable (SID) Debian distributions. A release for the armhf architecture is part of the Orthanc package. The file list of the orthanc package in the Debian stretch distribution for the armhf architecture is the following :


Orthanc Source Code

RPI’s are based on the ARM architecture and Raspbian releases usually follow the corresponding Debian release, but do deviate in a handful of cases. For this reason I preferred to build Orthanc version 1.0 from the source code, located on Bitbucket, on the Raspberry Pi hardware.

I downloaded the repository and put the content into a folder named Orthanc in the Raspberry Pi /home/pi/ directory. The following packages needed for compilation and linking have been installed first :

sudo apt-get install build-essential unzip cmake mercurial \
uuid-dev libcurl4-openssl-dev liblua5.1-0-dev \
libgoogle-glog-dev libgtest-dev libpng-dev libjpeg-dev \
libsqlite3-dev libssl-dev zlib1g-dev libdcmtk2-dev \
libboost-all-dev libwrap0-dev libjsoncpp-dev libpugixml-dev

I created a new folder OrthancBuild inside the /home/pi/ directory and executed the following commands :

cd OrthancBuild

During the configuration process, the following files have been downloaded from the website http://www.montefiore.ulg.ac.be/~jodogne/Orthanc/ThirdPartyDownloads/ :

All the files have been saved in a new folder orthanc-default/ThirdPartyDownloads. All the third-party dependencies are statically linked to the Orthanc build. The compilation takes more time (several hours), compared to the default behavior where system wide libraries are used. Statically linked builds are however easier to share and to clone.

The result of the compilation was the generation of the following files :

  • Orthanc (executable)
  • UnitTests (executable)
  • libServeFolders.so.mainline (shared library) -> renamed to libServeFolders.so
  • libModalityWorklist.so.mainline (shared library) -> renamed to libModalityWorklist.so
  • libCoreLibrary.a (AR archive)
  • libServerLibrary.a (AR archive)
  • libOpenSSL.a (AR archive)

Running the UnitTests shows that all 154 tests from 43 test cases passed, 2 tests were disabled.

Orthanc UnitTests

Orthanc UnitTests

Orthanc plugins

I used the same procedure to compile the plugins DICOMweb and WebViewer. The source code was copied into the folders /home/pi/Dicomweb/ and /home/pi/Webviewer/. I created the new folders /home/pi/DicomwebBuild/ and /home/pi/WebviewerBuild and finally executed the commands

cd /home/pi/DicomwebBuild

cd /home/pi/WebviewerBuild
cmake -DSTATIC_BUILD=ON -DCMAKE_BUILD_TYPE=Release ~/Webviewer

The following third-party libraries are used by the plugins :

Dicomweb Webviewer
boost_1_59_0 boost_1_59_0
GDCM-prefix GDCM-prefix
gtest-1.7.0 gtest-1.7.0
jsoncpp-0.10.5 jsoncpp-0.10.5

The shared libraries libOrthancDicomWeb.so.mainline and libOrthancWebViewer.so.mainline were created as a result of the compilation and linking process. I renamed these libraries without the mainline suffix.

The results of the UnitTests runs are shown hereafter :

Orthanc DicomWeb UnitTests

Orthanc DicomWeb UnitTests


Orthanc WebViewer UnitTests


The OrthancPi distribution files are assembled as follows in a directory named /home/pi/orthancpi/.

  • Orthanc  (executable)
  • UnitTests (executable)
  • configuration.json
  • /plugins/libServeFolders.so
  • /plugins/libModalityWorklists.so
  • /plugins/libOrthancDicomWeb.so
  • /plugins/libOrthancWebViewer.so.
  • /web/index.html (OrthancPi welcome page)
  • /python/ (empty)
  • /lua/ (empty)
  • /WorklistsDatabase/ (worklist samples)
  • /OrthancStorage/ (empty)

The default configuration.json file is created with the command

cd orthancpi
./Orthanc --config=configuration.json

I modified the configuration file as follows :

 // ***
 // General configuration of Orthanc
 // ***

 // The logical name of this instance of Orthanc. This one is
 // displayed in Orthanc Explorer and at the URI "/system".
  "Name" : "OrthancPi",

 // Path to the directory that holds the heavyweight files
 // (i.e. the raw DICOM instances)
  "StorageDirectory" : "OrthancStorage",

 // Path to the directory that holds the SQLite index (if unset,
 // the value of StorageDirectory is used). This index could be
 // stored on a RAM-drive or a SSD device for performance reasons.
  "IndexDirectory" : "OrthancStorage",

 // Enable the transparent compression of the DICOM instances
  "StorageCompression" : false,

 // Maximum size of the storage in MB (a value of "0" indicates no
 // limit on the storage size)
  "MaximumStorageSize" : 0,

 // Maximum number of patients that can be stored at a given time
 // in the storage (a value of "0" indicates no limit on the number
 // of patients)
  "MaximumPatientCount" : 0,
 // List of paths to the custom Lua scripts that are to be loaded
 // into this instance of Orthanc
  "LuaScripts" : [

 // List of paths to the plugins that are to be loaded into this
 // instance of Orthanc (e.g. "./libPluginTest.so" for Linux, or
 // "./PluginTest.dll" for Windows). These paths can refer to
 // folders, in which case they will be scanned non-recursively to
 // find shared libraries.
  "Plugins" : [
"Worklists" : {
    "Enable": true,
    "Database": "../WorklistsDatabase"
 "ServeFolders" : {
        "/web" : "/home/pi/orthancpi/web"

  "DicomWeb" : {
     "Enable" : true,
     "Root" : "/dicom-web/",
     "EnableWadoo" : true,
     "WadooRoot" : "/wado",
     "Host" : "localhost",
     "Ss1" : false

 // **
 //  Configuration of the HTTP server
 // **

 // Enable the HTTP server. If this parameter is set to "false",
 // Orthanc acts as a pure DICOM server. The REST API and Orthanc
 // Explorer will not be available.
  "HttpServerEnabled" : true,

 // HTTP port for the REST services and for the GUI
  "HttpPort" : 8042,

 // When the following option is "true", if an error is encountered
 // while calling the REST API, a JSON message describing the error
 // is put in the HTTP answer. This feature can be disabled if the
 // HTTP client does not properly handles such answers.
  "HttpDescribeErrors" : true,

 // Enable HTTP compression to improve network bandwidth utilization,
 // at the expense of more computations on the server. Orthanc
 // supports the "gzip" and "deflate" HTTP encodings.
  "HttpCompressionEnabled" : true,

 // **
 // Configuration of the DICOM server
 // **

 // Enable the DICOM server. If this parameter is set to "false",
 // Orthanc acts as a pure REST server. It will not be possible to
 // receive files or to do query/retrieve through the DICOM protocol.
  "DicomServerEnabled" : true,

 // The DICOM Application Entity Title
  "DicomAet" : "ORTHANCPI",

 // Check whether the called AET corresponds during a DICOM request
  "DicomCheckCalledAet" : false,

 // The DICOM port
  "DicomPort" : 4242,

 // The default encoding that is assumed for DICOM files without
 // "SpecificCharacterSet" DICOM tag. The allowed values are "Ascii",
 // "Utf8", "Latin1", "Latin2", "Latin3", "Latin4", "Latin5",
 // "Cyrillic", "Windows1251", "Arabic", "Greek", "Hebrew", "Thai",
 // "Japanese", and "Chinese".
  "DefaultEncoding" : "Utf8",

 // The transfer syntaxes that are accepted by Orthanc C-Store SCP
  "DeflatedTransferSyntaxAccepted"     : true,
  "JpegTransferSyntaxAccepted"         : true,
  "Jpeg2000TransferSyntaxAccepted"     : true,
  "JpegLosslessTransferSyntaxAccepted" : true,
  "JpipTransferSyntaxAccepted"         : true,
  "Mpeg2TransferSyntaxAccepted"        : true,
  "RleTransferSyntaxAccepted"          : true,

 // Whether Orthanc accepts to act as C-Store SCP for unknown storage
 // SOP classes (aka. "promiscuous mode")
  "UnknownSopClassAccepted"            : false,

 // **
 // Security-related options for the HTTP server
 // **

 // Whether remote hosts can connect to the HTTP server
  "RemoteAccessAllowed" : true,

 // Whether or not SSL is enabled
  "SslEnabled" : false,

 // Path to the SSL certificate (meaningful only if SSL is enabled)
  "SslCertificate" : "certificate.pem",

 // Whether or not the password protection is enabled
  "AuthenticationEnabled" : false,

 // The list of the registered users. Because Orthanc uses HTTP
 // Basic Authentication, the passwords are stored as plain text.
  "RegisteredUsers" : {
 // "alice" : "alicePassword"

 // **
 //  Network topology
 // **

 // The list of the known DICOM modalities
  "DicomModalities" : {
 // **
 //    * Uncommenting the following line would enable Orthanc to
 //    * connect to an instance of the "storescp" open-source DICOM
 //    * store (shipped in the DCMTK distribution) started by the
 //    * command line "storescp 2000".
 //   **
 // "sample" : [ "STORESCP", "localhost", 2000 ]
	"Horos" : [ "HOROS", "", 104 ],
	"dcm4che" : [ "DCM4CHE", "", 104 ]

// **
//    * A fourth parameter is available to enable patches for a
//     * specific PACS manufacturer. The allowed values are currently
//    * "Generic" (default value), "StoreScp" (storescp tool from
//    * DCMTK), "ClearCanvas", "MedInria", "Dcm4Chee", "SyngoVia",
//    * "AgfaImpax" (Agfa IMPAX), "EFilm2" (eFilm version 2), and
//     * "Vitrea". This parameter is case-sensitive.
//  **
// "clearcanvas" : [ "CLEARCANVAS", "", 104, "ClearCanvas" ]

 // The list of the known Orthanc peers
  "OrthancPeers" : {
 // **
//     * Each line gives the base URL of an Orthanc peer, possibly
//    * followed by the username/password pair (if the password
//    * protection is enabled on the peer).
//  **
// "peer"  : [ "http://localhost:8043/", "alice", "alicePassword" ]
// "peer2" : [ "http://localhost:8044/" ]
	"OrthancMac" : [ "" ]

// Parameters of the HTTP proxy to be used by Orthanc. If set to the
// empty string, no HTTP proxy is used. For instance:
//   "HttpProxy" : ""
//   "HttpProxy" : "proxyUser:proxyPassword@"
  "HttpProxy" : "",

// Set the timeout for HTTP requests issued by Orthanc (in seconds).
  "HttpTimeout" : 10,

// Enable the verification of the peers during HTTPS requests.
// Reference: http://curl.haxx.se/docs/sslcerts.html
  "HttpsVerifyPeers" : true,

// Path to the CA (certification authority) certificates to validate
// peers in HTTPS requests. From curl documentation ("--cacert"
// option): "Tells curl to use the specified certificate file to
// verify the peers. The file may contain multiple CA
// certificates. The certificate(s) must be in PEM format."
  "HttpsCACertificates" : "",

// **
// Advanced options
// **

// Dictionary of symbolic names for the user-defined metadata. Each
// entry must map an unique string to an unique number between 1024
// and 65535.
  "UserMetadata" : {
 // "Sample" : 1024

// Dictionary of symbolic names for the user-defined types of
// attached files. Each entry must map an unique string to an unique
// number between 1024 and 65535. Optionally, a second argument can
// provided to specify a MIME content type for the attachment.
  "UserContentType" : {
 // "sample" : 1024
 // "sample2" : [ 1025, "application/pdf" ]

// Number of seconds without receiving any instance before a
// patient, a study or a series is considered as stable.
  "StableAge" : 60,

// By default, Orthanc compares AET (Application Entity Titles) in a
// case-insensitive way. Setting this option to "true" will enable
// case-sensitive matching.
  "StrictAetComparison" : false,

// When the following option is "true", the MD5 of the DICOM files
// will be computed and stored in the Orthanc database. This
// information can be used to detect disk corruption, at the price
// of a small performance overhead.
  "StoreMD5ForAttachments" : true,

// The maximum number of results for a single C-FIND request at the
// Patient, Study or Series level. Setting this option to "0" means
// no limit.
  "LimitFindResults" : 0,

// The maximum number of results for a single C-FIND request at the
// Instance level. Setting this option to "0" means no limit.
  "LimitFindInstances" : 0,

// The maximum number of active jobs in the Orthanc scheduler. When
// this limit is reached, the addition of new jobs is blocked until
// some job finishes.
  "LimitJobs" : 10,

// If this option is set to "false", Orthanc will not log the
// resources that are exported to other DICOM modalities of Orthanc
// peers in the URI "/exports". This is useful to prevent the index
// to grow indefinitely in auto-routing tasks.
  "LogExportedResources" : true,

// Enable or disable HTTP Keep-Alive (deprecated). Set this option
// to "true" only in the case of high HTTP loads.
  "KeepAlive" : false,

// If this option is set to "false", Orthanc will run in index-only
// mode. The DICOM files will not be stored on the drive. Note that
// this option might prevent the upgrade to newer versions of Orthanc.
  "StoreDicom" : true,

// DICOM associations are kept open as long as new DICOM commands
// are issued. This option sets the number of seconds of inactivity
// to wait before automatically closing a DICOM association. If set
// to 0, the connection is closed immediately.
  "DicomAssociationCloseDelay" : 5,

  // Maximum number of query/retrieve DICOM requests that are
  // maintained by Orthanc. The least recently used requests get
  // deleted as new requests are issued.
  "QueryRetrieveSize" : 10,

// When handling a C-Find SCP request, setting this flag to "true"
// will enable case-sensitive match for PN value representation
// (such as PatientName). By default, the search is
// case-insensitive, which does not follow the DICOM standard.
  "CaseSensitivePN" : false,
// Register a new tag in the dictionary of DICOM tags that are known
// to Orthanc. Each line must contain the tag (formatted as 2
// hexadecimal numbers), the value representation (2 upcase
// characters), a nickname for the tag, possibly the minimum
// multiplicity (> 0 with defaults to 1), and possibly the maximum
// multiplicity (0 means arbitrary multiplicity, defaults to 1).
  "Dictionary" : {
// "0014,1020" : [ "DA", "ValidationExpiryDate", 1, 1 ]

I copied the whole orthancpi directory with an USB card reader to different Raspberry Pi modules which were configured to run as headless servers with remote control, using various wifi adapters. The process is explained in my post Rasperry Pi revisited.

To start the OrthancPi server at boot, a file orthanc.desktop has been added to the /home/pi/.config/autostart/ folder. This is the content of this file

[Desktop Entry]
Exec=/home/pi/orthancpi/Orthanc /home/pi/orthancpi/configuration.json

OrthancPi can also be configured to run as a Debian daemon.

An OrthancPi server will be used in the context of the RadioLogic project, a training tool for radiology. This tool will be used in classrooms without Internet access. The OrthancPi server works as wireless access point. To extend the WiFi range, a  repeater can be used. The RadioLogic tool is web based and optimized to run on iPad’s which are connected to the OrthancPi WLAN. The following figure shows two OrthancPi servers with USB WiFi adapters using  Ralink RT5370 chips.

OrthancPi's with USB WiFi adapters, SDcards and SDcard-reader

OrthancPi’s with USB WiFi adapters, SDcards and SDcard-reader

A user guide for the OrthancPi is available at the RadioLogic website. Disk image files to set up an OrthancPi server in a plug and play way, with different WiFi adapters, are available at the same webpage.

Raspberry Pi Revisited

Last update : March 20, 2016

Referring to my first post about the Raspberry Pi, I am pleased to provide an update about my ongoing projects, with a special focus on a wireless headless operation. Headless means running it without a mouse, keyboard and monitor, via network connections. Wireless means using a WLAN connection with a WiFi dongle.

Raspberry Pi's

Raspberry Pi’s with SDcards and WiFi dongles

Raspbian Jessie

A new Raspbian (the Raspberry Pi Foundation’s official supported operating system) version, based on Debian Jessie, was launched on November 21, 2015. Updates were released on February 9, February 26 and March 18, 2016. I upgraded my Raspberry Pi computers to the February 26 version (kernel 4.1.18+ on RPi 1 models; kernel 4.1.18-v7+ on RPi 2 and 3 models). I used the same procedure as last time : writing the downloaded Raspbian image with the Win32DiskImager tool on my Windows computer to 8GB and 16GB SDcards. The current version of this tool is 0.9.5, released on March 19, 2014.

Raspberry Pi model B

Raspberry Pi model B

It was not possible to overwrite the old Raspbian image on my Raspberry Pi SDcards with the new one. Reformatting the used SDcards with the usual tools (diskpart, SDCard Formatter 4, …) was not successful. Windows sees only the 56 MB FAT32 partition, but not the much larger Linux partition. It was not possible to recover the lost space. After some trials and errors, I finally reformatted the SDcards in my Nikon camera. It worked like a charm. Writing the new Raspbian image to the new formatted SDcards was then no problem.

Raspberry Pi model 2

Raspberry Pi model 2

Configuring Raspbian

After the first booting of the Raspberry Pi computer, the new desktop appears.

Raspian Jessie Desktop

Raspbian Jessie Desktop

The desktop contains only one icon : the Trash. The Raspberry logo is shown in the center. The menu is in the left upper corner, some icons are in the right upper corner. It’s possible to reconfigure the menu list. One new icon is the network configuration tool based on Roy Marples‘s dhcpcd and dhcpcd-ui packages.

The configuration panel allows to expand the filesystem.

Raspberry Pi Configuration

Raspberry Pi Configuration

After expanding and rebooting the system, the File Manager (PCManFM 1.2.3) shows a free space of 3,6 GB on my 8GB SDcard, compared to a free space of 98,1 MB before the expansion. The Raspbian Jessie version allows to set the locale to “lb” for Luxembourg in the localisation tab, and Luxembourg is also included as country in the timezone list. The french-swiss keyboard used in Luxembourg figures now, as expected, among the Switzerland keyboards.

The computer was recognized by my Fritzbox router and the IP address was assigned by the DHCP server.

Updating and checking the Raspbian version

The file /etc/apt/sources.list contains the following source (one line) :

deb http://mirrordirector.raspian.org/raspian/ 
jessie main contrib non-free rpi

I replaced mirrordirector by archive to avoid numerous download fails. To download the source code of packages with apt-get source, the following line should be un-commented in the sources.list file (one line) :

deb-src http://archive.raspian.org/raspian/ 
jessie main contrib non-free rpi

Raspbian Jessie is based on Linux version 8. A lite version without the GUI is separately available. I preferred to install the full version and to remove some large packages like Wolfram, Office and some games with the following command :

sudo apt-get remove --purge wolfram-engine libreoffice* minecraft-pi \
python-minecraftpi python3-minecraftpi

The files /usr/share/raspi-ui-overrides/applications/wolfram-mathematica.desktop and ../wolfram-language.desktop must be deleted to remove the related empty icons in the task bar.

To install the additional packages needed for the headless operation I entered the command :

sudo apt-get update
sudo apt-get install x11vnc hostapd dnsmasq lighttpd haveged

Lists of the resulting installed packages for my project are provided at the following links :

The default Raspbian terminal application is LXTerminal.

To upgrade all Debian packages to the latest version, I launched the well known commands

sudo apt-get update
sudo apt-get upgrade

in the terminal window. Two packages were upgraded. To show the installed versions, we can use the following commands :

  • uname – a        > kernel
  • lsb_release -a       > distribution
  • /opt/vc/bin/vcgencmd version       > firmware
  • cat  /proc/version
  • cat  /proc/cpuinfo     > CPU
  • cat  /proc/meminfo    > memory
  • cat  /proc/partitions    > partitions
  • cat  /etc/debian_version
  • cat  /etc/issue
Show Raspian Versions

Show Raspban versions and system informations

The command dmesg (display message or driver message) prints the message buffer of the kernel. An error “bcm2708_fb soc.fb: Unknown ioctl 0x40187a22” is listed.


display the Raspberry Pi kernel message buffer

Remote Control

There are several methods available to remotely control a headless Raspberry Pi computer. The most common are :

  • Secure Shell (SSH)
  • Remote Desktop (RDP)
  • Tight-VNC
  • X11-VNC


An SSH client is a software program which uses the secure shell protocol to connect to a remote computer. SSH provides a secure channel over an unsecured network in a client-server architecture. There are numerous SSH clients available for the different operating systems. For Windows an often used SSH program is PuTTY. PuTTY is a free and open-source terminal emulator, serial console and network file transfer application which was written and is maintained primarily by Simon Tatham.


Secure Shell Terminal PuTTY for Windows

The following security alert is displayed by the PuTTY terminal at the first connection to a new server.


PuTTY security alert

The next figure shows the welcome message sent by the Raspberry Pi after a successful login. The default user name is pi and the default password is raspberry.These parameters can be changed in the Raspbian configuration.


PuTTY welcome message

The Apple Mac computers have an integrated secure shell in the standard terminal program. A connection can be established with the following command :

ssh username@server

Secure shell in a MacBook Air

I use the WebSSH app for my iOS devices and the JuiceSSH app for my Android tablets.


Remote Desktop Protocol (RDP) is a proprietary protocol developed by Microsoft, which provides a user with a graphical interface to connect to another computer over a network connection. The user employs RDP-client software for this purpose, while the other computer must run RDP-server software.

To install the remote desktop server application XRDP (version 0.6.1-2) on Raspberry Pi, I launched the command

sudo apt-get install xrdp

The next figure shows the Remote Desktop Connection Panel on Windows :


XRDP Logon settings

RDP Clients exist not only for Windows and Windows Mobile, but also for OS X (version 8.0.24) , Linux, iOS (version 8.1.17) and Android.

The problem with european keyboards explained in my former Raspberry Pi contribution persist and is even more difficult to solve on tablets. For this reason I discarded the RDP solution for my future projects.


Tight-VNC is a cross-platform free and open-source remote desktop software application that uses and extends the remote framebuffer (RFB) protocol of Virtual Network Computing (VNC) to control another computer’s screen remotely. It was created by Constantin Kaplinsky.

Most tutorials about remote desktops refer to the Tight-VNC-Server as favorite solution. One disadvantage of this application is that it uses only virtual desktops, which is not optimal for a headless operation of a computer. Therefore I discarded the Tight-VNC-Server for my projects, but i use the Tight-VNC-Client on Windows as viewer to work with an X11-VNC-Server.


X11-VNC allows remote access from a remote client to a computer hosting an X Window (X11) session and the x11vnc server software, continuously polling the X server’s frame buffer for changes. X11-VNC does not create an extra display for remote control. Instead, it uses the existing X11-display shown on the monitor in real time.

To install an X11-VNC-server on Raspberry Pi, we enter the command

sudo apt-get install x11vnc

To start the server the first time we use the command

x11vnc -usepw -forever -display :0

A password (= raspberry) is defined at this first launch, verified and saved in the /home/pi/.vnc/ directory. The window 0 refers to the visible desktop and is related to the port number 5900. Additional virtual desktops can be configured with the display numbers 1, 2, 3 … and are associated with the port numbers 5901, 5902, 5903 … To launch the VNC-server automatically when the Raspberry Pi boots, we create an auto-start file


with the following content :

[Desktop Entry]
Exec=x11vnc -usepw -forever -display :0

A VNC viewer is installed at a remote computer to access the Raspberry Pi desktop. I use the free Tight-VNC-Viewer for Windows (version 2.7.10 released on July 24, 2013) and the RealVNC viewer for iOS (version 2.4.1 released on December 2, 2015). A VNC viewer is also available for Android (version released on February 11, 2016) and other operating systems. A VNC client is integrated in OS X an can be opened in Safari with the command

vnc://IP address:port number

The VNC-server takes the display size from the resolution of the connected HDMI monitor. In case of headless operation, the display size on the VNC viewer is very small. To adapt the display size to the iPad (my preferred VNC viewer), I uncommented and modified the following lines in the configuration file /boot/config.txt.


For security reasons I configured the VNC-server to be only accessible in the local network.

WLAN Adapters

To set up a WiFi connection to access the Raspberry Pi wirelessly, we need a WiFi dongle. I use the following 150Mbps Wireless N Nano USB adapters for my Raspberry Pi projects :

The Raspberry Pi 3 model has an onboard WiFi chip. The command lsusb shows the ID of the dongles, here for the official Raspberry WiFi adapter.


lsusb result for Raspberry dongle : Bus 001 Device 004 = Broadcom Corp. ID 0a5c:bd1e

The command lsmod shows which loadable kernel modules are currently loaded.


lsmod result for the Raspberry WiFi dongle

The modules related to the Broadcom WiFi dongle are brcmfmac, brcmutil and cfg80211. Detailed informations about these modules are obtained with the command modinfo modulename :


modinfo results for the Raspberry WiFi dongle

The associated preinstalled drivers and utilities are


In the case of a RPi 2 or 3 device, the module is /4.1.18-V7+/.

The command iw list shows the features of the installed WiFi dongle.

iw list results

iw list results for the Raspberry WiFi dongle

Among the listed features, the supported interface modes are the most important. The support of AP means that the WiFi dongle can be used as WLAN access point.

The command dmesg (display message or driver message) prints the message buffer of the kernel. The result shows an issue with the brcmfmac driver for the official Raspberry WiFi dongle.


brcmfmac errors issued by dmesg command

[ 11.060813] brcmfmac: brcmf_c_preinit_dcmds: 
Firmware version = wl0: Apr 3 2014 04:43:32 
version (r467479) FWID 01-32bd010e
[ 11.105542] brcmfmac: brcmf_cfg80211_reg_notifier: not a ISO3166 code
[ 14.284071] brcmfmac: brcmf_add_if: ERROR: netdev:wlan0 already exists
[ 14.284233] brcmfmac: brcmf_add_if: ignore IF event

Nevertheless the official WiFi dongle seems to work as expected.

Running the commands lsusb, lsmod and iwlist for the other 3 WiFi dongles and the onboard WiFi chip allows me to dress the following table :

Dongle Chipset ID WPA driver AP support
D-Link DWA-131 Realtek RTL8192CU 2001:330d 8192cu.ko yes
TP-Link TL-WN725N Realtek RTL8188EUS 0bda:8179 8188eu.ko yes
Raspberry WiFi Broadcom BCM43143 0a5c:bd1e brcmfmac.ko yes
Racksoy Mini Stick Ralink RT5370 148f:5370 rt2800usb.ko yes
RPI 3 onboard chip Broadcom BCM43438 ————- brcmfmac.ko yes

lsusb result for the Wifi dongle D-LINK DWA-131 (module 8192cu)

The command modinfo 8192cu confirms that the dongle with ID 2001:330d is supported by the preinstalled driver 8192.ko located at


The WiFi dongles Raspberry, Racksoy and D-Link DWA-131 work out of the box in my Raspberry Pi. The following figure shows the Raspian Desktop with the activated Wifi icon. The two pasted message panels show the informations displayed when the mouse hovers the WiFi icon : the first case with additional wired Ethernet connection, the second case without Ethernet connection.


Raspbian WiFi information panel

The next figure shows the information displayed in my Fritzbox gateway concerning the WLAN and the Ethernet connections of the Raspberry Pi :


Raspberry Pi connections listed in the Fritzbox home-network panel

The fourth WiFi dongle (TP-Link TL-WN725N) uses the Realtek rtl8188EUS chip. Out of the box, the dongle worked, but with a very low signal indicator, although the Raspberry Pi was near my WLAN gateway. The lsmod command shows a driver r8188eu among the currently loaded kernel modules. This driver r8188eu.ko is located in the folder


The Linux Staging tree is used to hold stand-alone drivers and filesystems that are not ready to be merged into the main portion of the Linux kernel tree, at this point in time, for various technical reasons. The correct driver named 8188eu.ko is not included in the Raspbian Jessie version. TP-Link and Realtek provide source files to compile the driver for specific Linux distributions. An installation guide is included in the zip-compressed driver file. Precompiled drivers for the Raspberry Pi are provided by the community. I used such a precompiled driver for my Linux version 4.1.18+, available at the following link :


The precompiled package with the 8188eu.ko driver contains a script install.sh to automatize the installation process. I preferred to do it manually. I installed the included driver 8188eu.ko into a new created folder rtl8188 inside the wireless driver directory with the commands

sudo install -p -m 644 8188eu.ko 
sudo depmod 4.1.18+

Finally I copied the included file 8188eu.conf, blacklisting the staging driver r8188 to the directory


modprobe is a Linux program used to add a loadable kernel module to the Linux kernel or to remove a module from the kernel.

After rebooting the dongle works as expected. For practical reasons I linked copies of the files 8188eu.ko and 8188eu.conf in the present post.


To connect the Raspberry to a remote WLAN Access Point, a software must run to provide WPA key negotiation with a WPA Authenticator and EAP authentication with an Authentication Server. The most common program for these tasks is wpa_supplicant, a free IEEE 802.11i software implementation developed by Jouni Malinen. In computer networking, a supplicant is an entity at one end of a point-to-point LAN segment that seeks to be authenticated by an authenticator attached to the other end of that link.

wpa_supplicant is a daemon and only one instance of it may run on a machine, all other modifications of security settings are made with the text-based frontend application wpa_cli. wpa_cli is used to query current status, change configuration, trigger events, and request interactive user input. wpa_supplicant is pre-installed in Raspbian Jessie.

wpa_cli status

wpa_cli status

wpa_cli works two ways: interactive and non-interactive

A list of some useful wpa_cli commands is shown below :

  • wpa_cli status
  • wpa_cli terminate

The following command can be used to restart the WiFi connection :

sudo /etc/init.d/networking restart

The wpa configuration file located at /etc/wpa_supplicant/wpa_supplicant.conf has the following content :

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev


To use a WiFi dongle in AP mode on Rasperry, you need hostapd or a similar application. wpa_supplicant allows basic AP configuration, but does not include support for most of the AP parameters. Comparing the hostapd.conf with the wpa_supplicant.conf example provides a picture of the difference.

The hostapd module is not pre-installed in Raspbian Jessie. The installation is done as usually with the command

sudo apt-get install hostapd

The version check after the successful installation shows version number 2.3.

hostapd version

hostapd version check

hostapd is developed and maintained by the author of wpa_supplicant, Jouni Malinen from Finland.

I edited the related configuration file


as follows for an open network :

# WLAN Router Configuration
# driver= autoselected

To protect and encrypt the network, the following parameters are added to the hostapd.conf file :

# WLAN Encryption 

Here is a link to my hostapd.conf file. Some explanations about the different configuration parameters used are listed below :

  • # : lines starting with an hash are considered as comments
  • interface : name of the interface to listen on
  • driver : usually detected by the system; in case of failure the name of the driver corresponding to the used dongle must be specified (nl80211, rtl871xdrv, …)
  • ssid : name of the network seen by other devices
  • ignore_broadcast_ssid : define if the network name is visible (broadcasted) or hidden
  • channel : WiFi channel used by the network; valid channels range from 1 to 11 or from 1 to 14, depending on the location
  • hw_mode : wireless mode : A, B and G are available; these are the last characters of the IEEE 802.11 standard. The most common is G (2,4 GHz).
  • wmm_enabled : WiFi multimedia to enhance quality of service (QoS)
  • auth_algs : specification of the authentication algorithm; 1 = OSA
  • country_code : used to set regulatory domain (transmit power, available channels)
  • ieee80211d : set the regulatory limits based on the country code
  • ieee80211n : optional activation of the IEEE 802.11n standard
  • wpa : security settings: 1=wpa; 2=wpa2; 3=wpa & wpa2
  • rsn_preauth :pre-authentication to speed up roaming
  • rsn_preauth_interfaces : list of interfaces from which pre-authentication frames are accepted
  • wpa_key_mgmt : management of the wpa2 WLAN keys; WPA-PSK or WPA-EA
  • rsn_pairwise : encryption algorithm for wpa2; new CCMP or old TKIP
  • wpa_pairwise : encryption algorithm for wpa
  • wpa_passphrase : password specified for the network
  • logger-syslog : instructions about error logging
  • max_num_sta : maximal number of clients accepted by the WLAN
  • deny_mac_file : prevent connections from devices with a MAC address specified in a file

The complete list of hostapd parameters is available at the website of the developer.

The Raspberry WiFi dongle works out of the box with the default hostapd driver nl80211. The Racksoy WiFi dongle works with the autoselected driver rt2800.

Hostapd supporting driver rtl871xdrv

The two other WiFi dongles D-Link DWA-131 and TP-Link TL-WN725N are not supported by the standard hostapd module with the included drivers. Both dongles use Realtek chipsets needing a specific driver, named rtl871xdrv. There are numerous posts and tutorials available at the web dealing with this problem, but only few provide correct and relevant solutions related to the current Raspbian Jessie version.

After some Trial and Error, I ended up with the following procedure :

  1. download the version 2.5 of the hostapd source https://w1.fi/releases/hostapd-2.5.tar.gz from the website https://w1.fi/hostapd/ of Jouni Malinen
  2. extract the archive at /home/pi/hostapd-2.5/
  3. clone the github repository https://github.com/pritambaral/hostapd-rtl871xdrv at /home/pi/hostapd-rtl871xdrv/ with the command
    sudo git clone https://github.com/pritambaral/hostapd-rtl871xdrv
  4. install the modules libnl1, libnl-dev and libssl-dev with the command
    sudo apt-get install libnl1 libnl-dev libssl-dev
  5. change directory to /home/pi/hostapd-2.5/
  6. apply the patch code with the command
    sudo patch -Np1 -i /home/pi/hostapd-rtl871xdrv/rtlxdrv.patch

    Patching the hostapd source

    Patching the hostapd source files

  7. enable the driver in the file .config with the commands
    cd hostapd
    cp defconfig .config
    echo CONFIG_DRIVER_RTW=y >> .config
  8. compile the hostapd module, inside the hostapd folder, with the following command
    sudo make install
  9. check the new installed hostapd version
hostapd version 2.5

hostapd version 2.5 for Realtek rtl871xdrv

The last step is to change the driver name as rtl871xdrv in the hostapd.conf file and to reboot the Raspberry Pi with a Realtek WiFi dongle. After terminating wpa_cli and starting hostapd, we get the confirmation that the Realtek dongles are now working.


hostapd launch with driver rtl871xdrv

Running Hostapd

Depending on the used WiFi dongle, we use the native hostapd version 2.3 or the new compiled version 2.5. Before associating hostapd with the wlan0 interface, we have to disassociate this interface with wpa_supplicant by entering the command

sudo wpa_cli terminate

To start the WLAN-Host, we run the command

sudo hostapd /etc/hostapd/hostapd.conf

Adding the optional parameter -dd (after hostapd) in the above command provides a detailed report about the process, which can be very helpful in case of problems. After a few moments the WiFi-panel in the Raspian desktop shows that the wlan0 interface is ssociated with the SSID “radiologic”. The interface is configured as AdHoc network with an self-assigned IP address in the range

WiFi panel when hostapd is started

WiFi panel when hostapd is started

I used an iPad as WLAN client to test the WLAN-Host. The SSID “radiologic” is displayed in the list of available WiFi networks as secured WLAN. After entering the defined password “123456789”, the connection is established. The next figure shows the related messages displayed in the Raspbian terminal window.

WLAN-Host messages for two connections and disconnections with an iPad

WLAN-Host messages for two connections and disconnections with an iPad

hostapd can be terminated by pressing simultaneously the keys  “Ctrl” and “c” .

To start hostapd at boot, we need to do some additional tasks. First we must uncomment and complete the parameter DAEMON_CONF in the file /etc/default/hostapd as follows :


We need to insert the same parameter in the init file /etc/init.d/hostapd.

Next we enable starting of hostapd at booting with the command

sudo systemctl enable hostapd
Enable autostart of hostapd at booting

Enable autostart of hostapd at booting

The new systemctl command synchronizes the booting process with the old legacy sysvinit command using update-rc.d. After a reboot we can check the status of the hostapd service with the command

service hostapd status


systemctl status hostapd
Show status of the hostapd service

Show status of the hostapd service

The following commands are used to stop, start, restart or disable hostapd :

sudo systemctl stop hostapd
sudo systemctl start hostapd
sudo systemctl restart hostapd
sudo systemctl disable hostapd

Hostapd needs random data to encrypt the WLAN. In computing, the randomness of data is called entropy. When the entropy is too low, “Add randomness” messages are displayed.


Raspberry messages related to randomness (entropy)

The entropy level can be checked with the command

cat /proc/sys/kernel/random/entropy_avail

When the returned value is less than 1.000, the entropy is unsufficient for secure cryptographic processes, which is often the case in small systems like the Raspberry Pi. Fortunately there is a solution :  HArdware Volatile Entropy Gathering and Expansion (HAVEGE).

The HAVEGE project is an attempt to provide an easy-to-use, unpredictable random number generator based upon an adaptation of the HAVEGE algorithm. The havege module is installed with the command

sudo apt-get install haveged

Another critical point related to hostapd is the power-save feature of most WiFi dongles. While this is a strong advantage when the WiFi dongle is in infrastructure mode (outbound) where the device is reactivated by the user, this is a great risk in AP mode when the computer works headless. In power-save mode, the WiFi dongle is no longer accessible by an external client and the only solution is to reboot the computer by unplugging and re-plugging the power supply.

We can check the status of power management with iwconfig.


Check the power management status of the WiFi dongle with iwconfig

To prevent the Wifi dongle from entering the power-save mode, we can add the command

wireless-power off

in the /etc/network/interfaces file.

Another possibility is to create configurations files in the directory /etc/modprobe.d/.

Examples for Realtek drivers :


options 8188eu rtw_power_mgnt=0


options 8192cu rtw_power_mgnt=0

Networking setup

Until now, the WiFi adapter has an auto-assigned IP address and the clients don’t receive an IP address when connecting to the WLAN, which is not a workable solution. We need a static IP address for wlan0 and a DHCP-server to attribute IP addresses to the WLAN clients.

Many tutorials about Raspberry Pi deal with static IP addresses to simplify the access to the RPI when the routing is managed by a DHCP-server. Most of them refer to the legacy ifupdown configuration file /etc/network/interfaces, which is obsolete with Raspbian Jessie using the DHCP-client dhcpcd developed by Roy Marples. The network configuration should be done in the file /etc/dhcpcd.conf. If a static IP address is required for the eth0 interface, a more simple way is to set it in the router of the local network. In my specific case this is a Fritzbox 7390. The best way however is to use the hostname of the Raspberry Pi to access it in the local network. The default hostname is raspberrypi. The hostname can be easily changed in the raspi configuration. The hostname is saved in the files /etc/hosts and /etc/hostnames.

The default configuration of /etc/network/interfaces to be used with dhcpcd is shown below:

# interfaces(5) file used by ifup(8) and ifdown(8)
# Please note that this file is written to be used with dhcpcd
# For static IP, consult /etc/dhcpcd.conf and 'man dhcpcd.conf'
# Include files from /etc/network/interfaces.d:
source-directory /etc/network/interfaces.d
auto lo
iface lo inet loopback
iface eth0 inet manual
allow-hotplug wlan0
iface wlan0 inet manual
wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf

The content of the default configuration of the /etc/dhcpcd file is the following :

# A sample configuration for dhcpcd.
# See dhcpcd.conf(5) for details.
# Allow users of this group to interact with dhcpcd via the control socket.
#controlgroup wheel
# Inform the DHCP server of our hostname for DDNS.
# Use the hardware address of the interface for the Client ID.
# or
# Use the same DUID + IAID as set in DHCPv6 for DHCPv4 ClientID as per RFC4361.
# Persist interface configuration when dhcpcd exits.
# Rapid commit support.
# Safe to enable by default because it requires the equivalent option set
# on the server to actually work.
option rapid_commit
# A list of options to request from the DHCP server.
option domain_name_servers, domain_name, domain_search, host_name
option classless_static_routes
# Most distributions have NTP support.
option ntp_servers
# Respect the network MTU.
# Some interface drivers reset when changing the MTU so disabled by default.
#option interface_mtu
# A ServerID is required by RFC2131.
require dhcp_server_identifier
# Generate Stable Private IPv6 Addresses instead of hardware based ones
slaac private
# A hook script is provided to lookup the hostname if not set by the DHCP
# server, but it should not be run by default.
nohook lookup-hostname

The lo interface (loopback) serves communication with localhost and is started automatically at boot. The IP address for the eth0 interface is requested by dhcpcd and provided by the LAN-router. The configuration for the wlan0 interface is provided by the /etc/wpa_supplicant/wpa_supplicant.conf file.

The status of the dhcpcd client is requested with the command

sudo systemctl status dhcpcd
dhcpcd status

Status of the dhcpcd client

For the headless operation of the Raspberry Pi with a WLAN Access Point I use a minimal network configuration :


# Legacy interface (ifupdown) file used with dhcpcd
auto lo
iface lo inet loopback
iface eth0 inet manual


# DHCPCD configuration
option rapid_commit
option domain_name_servers, domain_name, domain_search, host_name
option classless_static_routes
option ntp_servers
require dhcp_server_identifier
slaac private
nohook lookup-hostname
interface wlan0
static routers=

A static IP address ( can be attributed to wlan0 by means of the WiFi Network Panel opened by right clicking the WiFi icon in the task bar.


WiFi Popup Menu to manage panels

The data inserted in the WiFi Networks Settings are saved in the /etc/dhcpcd.conf file as shown above.


Network preferences wlan0 interface options


One piece of the puzzle is still missing : a Dynamic Host Configuration Protocol (DHCP) Server to provide IP addresses to the WLAN clients. There are several dhcp-server packages available for Raspbian. I selected dnsmasq, a very useful module to set up a complete WLAN router. dnsmasq is a Domain Name System (DNS) forwarder and a DHCP-server for small computer networks, which are easily configurable, with low usage of system resources.

dnsmasq is installed with the command

sudo apt-get install dnsmasq

The configuration is done in the file /etc/dnsmasq.conf. Here is a link to the content of the default dnsmasq.conf file. My minimal configuration is the following :

# DNSMASQ Configuration

The DHCP-server is restricted to the wlan0 interface, the eth0 interface is excluded. The range of IP addresses to attribute to the WLAN clients is bounded by 2 and 99 in the sub-network The lease time is 12 hours.

dnsmasq is managed with the same type of commands as hostapd :

sudo systemctl start dnsmasq
sudo systemctl stop dnsmasq
sudo systemctl restart dnsmasq
sudo systemctl enable dnsmasq 
sudo systemctl disable dnsmasq 
sudo systemctl status dnsmasq

Status of the dnsmasq server

To test the correct access with WLAN clients to the Raspberry Pi, we will use the installed web-server lighttpd. The configuration files for the web-server are located in the directory /etc/lighttpd/. The web pages are located in the folder /var/www/html/. By entering the URL

in a browser after logging into the radiologic WLAN, we can display the index web page. A screenshot of the default html index page is shown hereafter :

Default web

Default web page of the lighttpd web server

I replaced this page with the following minimal html script :

<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Welcome Page</title>
<style type="text/css">
h1, h3 {text-align:center}
<h3> to the Rasperry Pi WLAN</h3>

The following photo shows the result on various mobile devices accessing the radiologic WLAN.

iPad, iPhone, Samsung, LG and Blackberry mobile devices conncetd to the Blackberry Pi WLAN

iPad, iPhone, Samsung, LG and Blackberry mobile devices connected to the RPi WLAN

Currently the clients can only access the embedded web server. If we want that the WLAN clients have access to the global Internet or to other services, we need to add more network configuration parameters or specific applications. This will be a topic of further contributions.

Service Management

As a last step we check that all programs are running without errors and that the performance of the system is correct. First we need to understand the boot process.

Debian separates the legacy boot process (based on System V init)  into seven runlevels labeled as 0, 1, 2, 3, 4, 5, 6 and S. For each runlevel a file rcx.d (x = 0, 1, 2, …) exist in the directory /etc/ containing symbolic links to targets located in /etc/init.d/. The runlevels are defined as follows :

  • 0 : (halt) stop all services and make the system ready for shutdown
  • 1 : (minimal mode) stop all services and put the system in single-user rescue mode
  • 2 – 4 : multiuser network enabled text mode
  • 5 : multiuser network enabled graphical mode
  • 6 : (reboot) stop all services, make the system ready for reboot
  • S : (single) these scripts are executed once

When we enable a service to auto-start, we are adding it to a runlevel.

Default Debian installation does not make any difference between runlevels 2-5. Number 2 is the default runlevel at start. In a normal boot the levels progress up to 5. Runlevels S  and 1 are used for maintenance. Runlevels can be edited manually by editing control scripts in /etc/init.d and symbolic links in /etc/rc0.d … /etc/rc6.d. The runlevel can also be changed at runtime with the command telinit [runlevel 2-5]. The current runlevel is indicated with the command runlevel.

Looking at the list of the services included in the /etc/init.d/ folder, we discover among others the installed programs dnsmasq, dhcpcd, haveged, hostapd and lighttpd.


Content of the folder /etc/init.d/

Here is an extract from the init.d README file :

# Provides: skeleton
# Required-Start: $remote_fs $syslog
# Required-Stop: $remote_fs $syslog
# Should-Start: $portmap
# Should-Stop: $portmap
# X-Start-Before: nis
# X-Stop-After: nis
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# X-Interactive: true
# Short-Description: Example initscript
# Description: This file should be used to construct scripts to be
# placed in /etc/init.d.

For each program defined as script in the /etc/init.d/ folder we can specify the runlevels for start and stop and the dependencies with other programs. The next figure shows a real example of an init-script related to the dnsmasq service :

init.d dnsmasq

init script related to dnsmasq in the /etc/init.d/ folder

We see that the virtual boot facilities $network, $remote_fs and $syslog must be started or stopped before the dnsmasq service. Creating init scripts manually is an error-prone task. For this reason the legacy System V (SysV) init program has now been replaced by new init systems. Raspbian Jessie is using systemd as service manager. We have already seen the related tool systemctl to start, stop, enable and disable programs.

In systemd, the targets of most actions are units, which are resources that systemd knows how to manage. Units are categorized by the type of resource they represent and they are defined with unit files. The systemd files are located in the directories /lib/systemd/system/ and /etc/systemd/system/.

Some useful systemd commands are listed below :

systemctl is-active application.service
systemctl is-enabled application.service
systemctl is-failed application.service
systemctl list-units
systemctl list-units --all
systemctl cat application.service
systemctl list-dependencies application.service
systemctl show application.service
sudo systemctl mask application.service
sudo systemctl unmask application.service
sudo systemctl edit application.service
systemctl get-default

For most commands the .service suffix can be omitted. Some real commands concerning hostapd are shown in the next figure :

results of some systemd systemctl commands

Results of some systemctl commands for hostapd

systemd has some great built-in tools to check and tune the boot time. The commands

systemd-analyze blame

will print the boot time respectively print the list of the most time-consuming services in decreasing order.

systemd-analyze results

systemd-analyze results

The command

systemd-analyze plot > init_plot.svg

creates an xml svg file which can be rendered in a browser. It displays in a graphical way when all the services start.

init_plot.svg file rendered in browser; click to enlarge

init_plot.svg file rendered in browser; click to enlarge

systemd has also a powerful tool to view and manipulate system logs named journald. The related configuration file is located in /etc/systemd/journald.conf. Some useful commands are :

journalctl --all 
journalctl --since=yesterday

journald provides various filters using time constraints. Logs can be viewed in UTC or local time at will. The following journald commands deal with time and date.

timedatectl list-timezones
sudo timedatectl set-timezone zone
timedatectl status

systemd tools : timedatectl and journalctl

journald provides other filter options than time constraints : units, users, groups, processes, pathes, priorities, … The journal display can be customized in various formats. The amount of space occupied by the journal on the SD card can be shown with the the command

journalctl --disk-usage

Backup and Cloning

When a bad shutdown has corrupted the file system, the Raspberry Pi can be a frustrating experience. It’s therefore useful to wait for the complete shut down of the RPi before unplugging the power supply. To shutdown or reboot the Raspberry Pi, we can use the menu “Shutdown” in the VNC-desktop


End Raspberry session with shutdown, reboot or logout

or the commands

sudo shutdown
sudo reboot

It’s also important to make at regular times a backup of the Raspberry Pi SDcard. Backups are possible on Windows 7 systems (or later) with the Win32DiskImager tool. First an image of the source card is saved to a file on the Windows PC. In an second step this image is copied to a backup SDcard. Backup’s can also be done with the Raspberry Pi itself by using an SDcard reader with USB interface.

Cloning a SDcard is the same procedure as doing a backup, but the goal is different. Cloning allows to distribute a complete mirror of a working RPi system with operating system, applications and data. This way it’s easy to copy and multiply an existing solution.

Sometimes a cloned image file can’t be copied to an SDcard with the same capacity, because SDcards can vary a little bit in size. There are several tutorials on the net how to solve this problem by shrinking the image file, for example one by Andrew Aokley, another one on the Wonky Gibbon Ramblings Blog.

I used the following procedure on my Debian computer :

df -h
cd /home/mbarnig/Desktop/
sudo dd if=/dev/sdb2 of=myimage.img bs=4M
sudo dd if=myimage.img of=/dev/sdb2 bs=4M conv=notrunc,noerror


The following list provides links to websites with additional informations about the Raspberry Pi :

Raspberry Pi

Dernière mise à jour : 23 janvier 2016

Le Raspberry Pi est un nano-ordinateur monocarte à processeur ARM développé par la fondation Raspberry Pi. Cet ordinateur, qui a la taille d’une carte de crédit, est destiné à encourager l’apprentissage de la programmation informatique; il permet l’exécution de plusieurs variantes du système d’exploitation libre GNU/Linux et des logiciels compatibles. Seule la carte mère nue est fournie, sans boîtier, alimentation, mémoire, clavier, souris ni écran, afin de diminuer les coûts et de permettre l’utilisation de matériel de récupération.

Ordinateur Raspberry Pi modèle B

Ordinateur Raspberry Pi modèle B

Raspberry Pi

Les ordinateurs Raspberry Pi et les accessoires afférents sont disponibles auprès de différents distributeurs et revendeurs, parmi eux Amazon. Fin 2015, il y  a quatre modèles disponibles : PI 1 A+, PI 1 B+, PI 2 B et PI Zero. Dans le passé il y avait encore les modèles PI 1 A et PI 1 B.

La documentation officielle est disponible sur le site web de la fondation. Je dispose d’un ensemble d’ordinateurs Raspberry Pi modèle B rev. 2 (2011.12), avec des modules de caméra Raspicam et des kits Bright Pi 1.0. Les caractéristiques principales sont présentées ci-après :
Ordinateur :

  • System on a chip (SoC) processeur : Broadcom BCM2835, 700 MHz (ARM, distribution armhf)
  • RAM : 512 MByte
  • Carte mémoire : Full SD
  • Ethernet : 10/100 Mbits
  • HDMI port : 1
  • USB 2.0 ports : 2
  • Composite video output : Cinch
  • Audio output : 3,5 mm audiojack
  • Camera interface CSI-2 : 1
  • LCD display interface DSI : 1
  • Extensions : 26
  • Nombre de GPIO (general purpose input/output) : 17
  • Alimentation : microUSB, 5 Volt, 700 mA

Caméra :

  • Sensor : OmniVision OV5647
  • Résolution : 2.592 x 1.944 pixels
  • Focus : fixe >= 1m
  • Vidéo : 1080p30, 720p60 and 640x480p90

Bright Pi v1.0 :

  •  interface I2C
  • 4 LED’s bright white
  • 8 LED’s Infrarouge


Comme j’utilise déjà Debian sur un autre ordinateur, je me suis décidé d’installer la version Debian adaptée au Raspberry Pi, appelée Raspbian, sur mes nano-ordinateurs.

Carte mémoire 8GB reformatée

Carte mémoire 8GB reformatée

Le système d’exploitation Raspbian, les autres logiciels et les données sont enregistrés sur une carte mémoire SD 8GB classe 10. Comme ma carte SD n’était pas vierge, mais formatée sur un autre système, la procédure de reformatage classique ne fonctionnait pas.

J’ai procédé comme suit dans le terminal de commande Windows :

list disk
select disk 1
format fs=FAT32 quick

Pour installer le système d’exploitation sur la carte mémoire, j’ai utilisé l’outil Win32DiskImager. La version la plus récente est 0.9.5. Les instructions comment procéder” sont disponibles sur le site web de l’organisation Raspberry Pi.

Outil Win32DiskImager

Outil Win32DiskImager


J’ai connecté le module camera (Raspicam) à la platine Raspberry PI sur base des instructions de set-up données sur le site web de Raspberry. Les caractéristiques sont indiquées dans les détails techniques. La caméra a été fixée sur un support spécifique.

Raspicam avec support

Raspicam avec support

Des bibliothèques (logiciels) pour piloter la caméra sont disponibles pour bash et pour Python. Les trois commandes de base en ligne pour gérer la caméra sont :

Les détails des commandes sont décrits dans l’API du module Raspicam.

Bright Pi

Bright-Pi module

Bright-Pi module

Bright Pi est un kit d’éclairage pour ajouter à la caméra Raspicam, développé par Pi Supply. Le module comprend 4 LED’s Cree blanches puissantes et 8 LED’s Liteon infrarouge.

J’étais un supporteur du projet Bright Pi sur Kickstarter.

Les éléments du module sont fournis séparément, il faut soi-même les assembler et souder. Les instructions d’assemblage et de programmation sont disponibles sur le site web de Pi-Supply.

Bright Pi utilise le bus I2C pour échanger des données avec le Raspberry Pi moyennant le chip Semtech SC620 (voir datasheet). Pour activer le bus I2C dans Raspian, il faut ajouter les deux lignes


à la fin du fichier /etc/modules. Pour ce faire, on peut utiliser l’éditeur nano sur Raspberry Pi. Pour sauver le fichier modifié, on pousse <Ctrl>+o, ensuite <Ctrl>+x pour quitter l’éditeur. La prise en compte des nouveaux modules se fait lors d’un reboot. Pour installer les outils i2c, il faut entrer les commandes

pi@raspberrypi ~ $ sudo apt-get install python-smbus
pi@raspberrypi ~ $ sudo apt-get install i2c-tools

Pour voir les modules connectés, on peut entrer la commande

pi@raspberrypi ~ $ sudo i2cdetect -y 1
Détection des modules connectés au bus I2C

Détection des modules connectés au bus I2C

On voit qu’un seul module avec l’adresse 0x70 est connecté, le Bright Pi. Pour piloter le module Bright Pi, on utilise la commande

i2cset [-y] i2cbus chip-address data-address value

Les paramètres sont :

  • -y : option pour désactiver le mode interactif (pas de confirmation nécessaire)
  • i2cbus : 1
  • chip-address : 0x70
  • data-address : 0x00 LED’s on/off; 0x01, 0x03, 0x06, 0x08 dimming IR LED’s couples; 0x02, 0x04, 0x05, 0x07 dimming white LED’s; 0x09 gain register
  • value : dimming values : 6 bit multipliers; gain values :0000 = 31,25 microampère; 1111 = 500 microampère; max = 25 millampère par LED

Quelques exemples sont montrés ci-après :

white LED1 12 mA : sudo i2cset -y 1 0x70 0x02 ...
white LED2 1 mA :
white LED3 


Comme alimentation, j’utilise le chargeur d’une tablette qui fournit 2 ampères à 5 Volt. Lors de la première mise sous tension, le Raspberry se configure automatiquement. Il ne reconnaît toutefois pas le layout de mon clavier luxembourgeois QWERTZ (respectivement français-suisse) et il faut le modifier manuellement comme suit :

pi@raspberrypi ~ $ sudo raspi-config


Le menu 4 (International Options) donne accès sélections “Change Locale”, “Change Timezone” et “Change Keyboard Layout”. Mon clavier Microsoft Wired Keyboard 600 ne fait pas partie des claviers figurant dans la liste déroulante des modèles de clavier. J’ai choisi le clavier Generic 105-key (Intl) PC. Un layout luxembourgeois n’est pas relevé, le layout du clavier français-suisse figure parmi les layouts allemands. Faut le savoir !

Via le menu 4 on peut également changer le fuseau horaire (le Luxembourg figure sur la liste des pays européens) et la langue d’affichage, par exemple pour passer en français.

Remote Desktop

Avant de pouvoir entrer des commandes il faut faire un login au système. Les paramètres par défaut pour le login sont : user name = pi ; password = raspberry. L’adresse IP attribuée par DHCP est Pour pouvoir piloter dans l’avenir ce Raspberry, et dans la suite ses confrères, à partir de mes ordinateurs connectés en réseau local, j’ai installé le service RDP (Remote Desktop Protocol) de Microsoft sur le Raspberry Pi :

pi@raspberrypi ~ $ sudo apt-get install xrdp

Après un redémarrage du Raspberry (commande sudo reboot ou sudo poweroff), le serveur xrdp sesman est configuré pour démarrer automatiquement lors de chaque mise sous tension.

Sur les ordinateurs Windows, le service RDP est disponible d’office et peut être démarré avec le menu Accessories/Remote Desktop Connection.

Microsoft Remote Desktop Connection

Microsoft Remote Desktop Connection

Après l’établissement de la connexion, le Raspberry retourne un avertissement


Avertissement RDP

et ensuite la fenêtre de login suivante (module sesman-Xvnc) :

XRDP Login Window

XRDP Login Window

Ici on découvre le prochain bug. Le clavier français-suisse de mon PC Windows n’est pas supporté par le service xrdp, mais il est interprété comme un clavier anglais. Il faut donc saisir le mot de passe raspberrz au lieu de raspberry pour réussir le login. Faut le savoir !

Support du clavier français-suisse par xrdp

Linux xrdp utilise par défaut le fichier keymap /etc/xrdp/km-0409.ini (us-english) si un fichier keymap non-existant est demandé. Il semble que le client Windows xrdp demande le keymap 20409 non disponible, indépendamment du clavier connecté. Le seul remède consiste à remplacer dans Raspian le fichier km-0409.ini par le contenu du fichier keymap du clavier utilisé. Dans mon cas il s’agit du fichier km-100c.ini (voir liste des keymaps).

On peut générer ce fichier avec la commande

pi@raspberrypi ~ $ sudo xrdp-genkeymap /etc/xrdp/km-100c.ini

Attention : il faut toutefois passer en mode graphique avec la commande startx et ouvrir le LXTerminal pour passer la commande, si non on obtient le message d’erreur << unable to open display ” >>.

Cliquez sur le fichier km-100c.ini pour visualiser son contenu. Il faut encore modifier le code de quelques touches qui ne sont pas reconnus correctement. Il s’agit notamment des combinaisons <alt-gr> et des touches curseur :

  • @
  • #
  • ~
  • ¢
  • ¬
  • up

Les touches mortes (dead keys) fonctionnent correctement.

Il suffit ensuite de renommer le fichier km-0409.ini en km-0409-old.ini et de copier le fichier km-100c.ini en km-0409.ini. Faut le savoir !


Après vérification de l’authenticité de l’usager, le desktop du Raspberry se présente sur l’écran et réagit aux commandes du clavier et de la souris.

Raspberry Pi's Desktop

Raspberry Pi’s Desktop

Les programmes et applications installés d’office sur le Raspberry Pi sont :

Je me propose d’ajouter les programmes suivants :

Pour activer la caméra, il faut passer dans le menu 5 (Enable Camera) de raspi-config. Pour tester la caméra et faire une première photo, on entre la commande

pi@raspberrypi ~ $ raspistill -o camtest1.jpg

Si la caméra est positionnée à l’envers, il faut tourner l’image de 180 degrés. Cela se fait aisément avec les options “vertical flip” et “horizontal flip”.

pi@raspberrypi ~ $ raspistill -vf -hf -o camtest2.jpg


Les liens suivants fournissent des informations additionelles concernant des projets Raspberry et le clavier XRDP :