Table of Contents for
Expanding Your Raspberry Pi: Storage, printing, peripherals, and network connections for your Raspberry Pi

Version ebook / Retour

Cover image for bash Cookbook, 2nd Edition Expanding Your Raspberry Pi: Storage, printing, peripherals, and network connections for your Raspberry Pi by Mark Edward Soper Published by Apress, 2017
  1. Cover
  2. Frontmatter
  3. 1. Raspberry Pi System Anatomy
  4. 2. The Distro Bunch
  5. 3. Adding Mass Storage
  6. 4. Connecting to a Workgroup Network
  7. 5. Sharing an Internet Connection
  8. 6. Setting Up a Print and Scan Server
  9. 7. Imaging and Video
  10. 8. Media Serving
  11. 9. GPIO Anatomy and Applications
  12. 10. Taking Your Raspberry Pi on the Road
  13. Backmatter

© Mark Edward Soper 2017

Mark Edward Soper, Expanding Your Raspberry Pi, https://doi.org/10.1007/978-1-4842-2922-4_6

6. Setting Up a Print and Scan Server

Mark Edward Soper1 

(1)Indianapolis, Indiana, USA

To turn your Raspberry Pi into a print and scan server, you need to perform the following tasks, all of which are covered in this chapter:

  • Connect your printer, scanner, or multifunction (print/scan/copy) device to your Raspberry Pi

  • Install and configure CUPS (Common Unix Print Service) on your Raspberry Pi

  • Create users that can connect remotely to a CUPS printer

  • Install and configure SANE (Scanner Access Now Easy) on your Raspberry Pi

  • Create users that can connect remotely to a SANE scanner

  • Install CUPS or SANE clients (if necessary) to remote systems that will connect to the printer, scanner, or multifunction device

There is also an optional task:

  • Configuring the Raspberry Pi for headless booting and remote control with SSH

Hardware Used in This Chapter

  • A multifunction unit (print/scanner/copier)

  • Raspberry Pi Node Zero (or other Raspberry Pi model using flash memory or a hard disk [recommended])

Connecting via USB

Most printers or multifunction (print/scan/copy) devices connect via USB. However, unlike Windows or MacOS (OSX), which can automatically detect USB devices, you must manually configure a printer or multifunction device after you connect it to your Raspberry Pi.

Caution

Boot your computer, log into it, and then connect your printer or multifunction device. If you connect the printer/device first, you could cause a kernel panic because Raspbian or other OSes will try to read the USB port or card reader.

If you use a Raspberry Pi Zero, ZeroW, 1, or 1+, you have only one USB port. If you need more than one USB port (for example, for a wireless or wired network adapter or a USB drive), be sure to choose a supported USB hub that has its own power supply. See http://elinux.org/RPi_Powered_USB_Hubs for a large list of tested hubs.

Caution

Some powered USB hubs can use one USB port to power some Raspberry Pi models. Be sure to review the notes on the eLinux page listed in the preceding paragraph to determine which hubs can do this.

Selecting a Distro

To reduce computing overhead and space requirements, it makes sense to use a GUI-less Linux distro such as Raspbian Jessie Lite for your print and scan server.

Note

Because of the limited lifespan of flash memory cards when used for frequent writes, I recommend installing Raspbian Jessie Lite or other Linux distros to a hard disk drive. I used the Pi Node Zero from WDLabs, which features a low-power 2.5-inch WD hard disk drive and a built-in two-port USB hub. For more information about using Pi Node Zero and other hard disks with Raspberry Pi, see Chapter 3.

Manual Connections to a Wireless Network

To install CUPS, Samba, and drivers for your printer and scanner, you need to connect to the Internet.

If you use a wireless network, it might be necessary to manually configure Raspbian Jessie Lite to use it. Here are two clues that your system doesn’t have a working wireless connection :

  • Running an apt-get command results in errors (Figure 6-1)

    A440135_1_En_6_Fig1_HTML.jpg
    Figure 6-1. Errors such as Temporary failure resolving… or Failed to fetch while running an apt-get command indicate a lack of a network connection

  • ifconfig doesn’t display a valid address for your wireless adapter (Figure 6-2)

    A440135_1_En_6_Fig2_HTML.jpg
    Figure 6-2. wlan0 has no IPv4 (inet) address, indicating it has no network connection

To set up a wireless configuration , follow these steps:

  1. Open the wpa_supplicant.conf file for editing [nano is the default text editor]:

    sudo nano /etc/wpa_supplicant/wpa_supplicant.conf

  2. Add the following statements to the end of the file (use your actual SSID and encryption key in place of the placeholders):

    network={
        ssid="YourSSID"
        psk="YourEncryptionKey"
    }

  3. To save changes, press Ctrl-X, then Y when prompted.

  4. Reboot: sudo reboot.

  5. After rebooting, run sudo ifconfig wlan0 to verify that you now have a working Internet connection (Figure 6-3).

    A440135_1_En_6_Fig3_HTML.jpg
    Figure 6-3. After rebooting, wlan0 now has a valid IPv4 (inet) address received from the DHCP server in the wireless router

  6. Be sure to note the IP(v4) address of your Raspberry Pi. In Figure 6-3, it is 192.168.1.154. You will use the Pi’s IP address to connect to CUPS remotely.

Installing and Using CUPS

After verifying that you have a working Internet connection, the next step is to update your system and install CUPS:

sudo apt-get update              
sudo apt-get install cups
Note

Depending upon the printer or multifunction unit you use, CUPS might already include drivers for your device, or you might need to add drivers. See “Installing Printer Drivers,” in this chapter for details.

Adding Users to the Print Administration Group

Unless you add your account to the Print Administration group, the only user that can administer print jobs would be root (su). Switch to the root (su) account with sudo su and use the usermod command to add your user account (pi) to the group:

usermod -a -G lpadmin pi

To view the groups a particular user (pi) belongs to:

groups pi

Figure 6-4 illustrates the groups user pi belongs to before and after using usermod.

A440135_1_En_6_Fig4_HTML.jpg
Figure 6-4. Adding the user pi to the lpadmin group

To return to the normal user account, enter the command exit.

Configuring CUPS for Remote Administration

The next step in setting up a printer is to run CUPS to name the printer and install the appropriate printer driver. However, CUPS is configured from a web browser. By editing the CUPS configuration file (cupsd.conf), we can allow remote administration via another computer’s web browser:

sudo nano/etc/cups/cupsd.conf

Make the following changes:

  • Replace Listen localhost: 631 with Port 631

  • In the sections headed <Location />, <Location /admin>, <Location /admin/conf>, add the line

Allow @local after the line Order allow, deny

Save changes by pressing Ctrl-X, Y.

Restart with

sudo service cups restart

Logging into CUPS Remotely

If you are using an older printer or multifunction device, it’s likely that CUPS already has a suitable printer driver. In this section, you learn how to log into CUPS from a remote computer’s web browser, select a printer, and configure it.

To connect to your Raspberry Pi from another computer on the network:

  1. Open a web browser.

  2. Enter the Pi’s IP(v4) address (replace the xxx in the following example with the actual number) and port number into the browser window: xxx.xxx.xxx.xxx:631.

  3. The CUPS home tab appears (Figure 6-5).

    A440135_1_En_6_Fig5_HTML.jpg
    Figure 6-5. Logging into CUPS remotely

Selecting and Configuring a Printer with CUPS

After opening CUPS, click Adding Printers and Classes to start the printer selection process :

  1. Click the local printer

  2. Click Continue (Figure 6-6)

    A440135_1_En_6_Fig6_HTML.jpg
    Figure 6-6. Starting the Add Printer process

  3. On the next dialog, enter the location (optional)

  4. Click the empty Share This Printer box to check it

  5. Click Continue (Figure 6-7)

    A440135_1_En_6_Fig7_HTML.jpg
    Figure 6-7. Specifying the location and enabling printer sharing

  6. Select the printer make (if not already selected) and model

  7. Click Add Printer (Figure 6-8)

    A440135_1_En_6_Fig8_HTML.jpg
    Figure 6-8. Adding the printer

    Note If you do not find your printer model, you have two options: select a similar model and see if it works by creating a document and printing it, or download and install the correct printer driver (next section) and rerun CUPS afterward.

  8. Select the options desired for the printer, such as the default paper size, media type, and print quality (Figure 6-9) on the General tab.

    A440135_1_En_6_Fig9_HTML.jpg
    Figure 6-9. Setting default options for the printer

  9. Click other tabs to set up all desired options.

  10. Click Set Default Options when you are finished.

Installing Printer Drivers

If your printer or multifunction device is not listed in CUPS and a satisfactory substitute driver is not available, you need to download the correct driver.

Note

To support a multifunction device for printing and scanning, you need to use CUPS (for printing) and SANE (for scanning). See “Installing and Configuring SANE,” in this chapter.

To search for printer drivers to install, use the apt-cache search command (replace printerdriver with the actual brand of printer):

sudo apt-cache search printerdriver
Note

apt-cache can also be used to display details of a particular package (sudo apt-cache show pkgname) or dependencies (sudo apt-cache showpkg pkgname). For more information, see www.tecmint.com/useful-basic-commands-of-apt-get-and-apt-cache-for-package-management/ .

In Figure 6-10, I searched for an Epson printer driver with sudo apt-cache epson. The search located several utility packages as well as the actual Epson printer driver I needed.

A440135_1_En_6_Fig10_HTML.jpg
Figure 6-10. Searching for printer drivers and utiliies with the apt-cache search command

To install the printer driver, use this command replace printer-driver-yourprinter with the actual printer driver file name):

sudo apt-get install printer-driver-yourprinter
Tip

For most HP printers and multifunction devices, download and install HPLIP (the HP Linux Printing and Imaging system).

Installing and Configuring Samba

To enable your Raspberry Pi to receive print and scan jobs, install and configure Samba, which provides SMB/CIFS file and print support to network clients running Windows, Linux, or MacOS (OSX) operating systems. Installing Samba is easy:

sudo apt-get install samba

After Samba is installed, use this command to open and edit its configuration files :

sudo nano /etc/samba/smb.conf

Make the following changes to the [global] section (replace Workgroup_name with the actual name of your workgroup) and add the security = user command:

workgroup = Workgroup_name
   ...
security = user

In the [printers] section make sure the browseable and guest OK settings are set to yes:

browsable = yes
guest ok = yes

Press Ctrl-X, Y to exit and save changes. To complete the process, restart Samba:

sudo /etc/init.d/samba restart

The default Samba configuration will automatically share any printers installed.

Connecting to a Samba Print Server with Windows

To connect to a Samba print server using Windows 7 :

  1. Open Control Panel.

  2. Click View Devices and Printers.

  3. Click Add a printer.

  4. Click Add a network, wireless, or Bluetooth printer (Figure 6-11).

    A440135_1_En_6_Fig11_HTML.jpg
    Figure 6-11. Searching for a network printer

  5. Click Next.

  6. Select the printer (Figure 6-12).

    A440135_1_En_6_Fig12_HTML.jpg
    Figure 6-12. Selecting the network printer

  7. Click Next .

  8. Click OK on the No driver found alert.

  9. Select the printer name and model from the Add Printer Wizard dialog (Figure 6-13).

    A440135_1_En_6_Fig13_HTML.jpg
    Figure 6-13. Selecting the printer driver

  10. Click OK.

  11. Click Next.

  12. If you want to use this printer as the default, click the Set as the default printer check box (Figure 6-14).

    A440135_1_En_6_Fig14_HTML.jpg
    Figure 6-14. Finishing printer setup

  13. Click Print a test page.

  14. Click Close.

  15. Click Finish.

To connect to a Samba print server using Windows 8.1 or 10:

  1. Open Settings.

  2. Click Devices.

  3. Click Printers & scanners.

  4. Click Add a printer or scanner (Figure 6-15).

    A440135_1_En_6_Fig15_HTML.jpg
    Figure 6-15. Starting the Add a printer process in Windows 10

  5. Click The printer that I want isn’t listed.

  6. Click Select a shared printer by name.

  7. Click Browse.

  8. Click the Raspberry Pi (default name RASPBERRYPI), then click Select.

  9. Click your printer, then click Select.

  10. Click Next (Figure 6-16).

    A440135_1_En_6_Fig16_HTML.jpg
    Figure 6-16. Selecting the printer by name

  11. Click OK on the No driver found alert.

  12. Continue with Steps 8-14 from the Windows 7 instructions. Close Settings after you are finished.

Note

If your printer is not listed in the Add Printer Wizard dialog, quit the process, download and install the appropriate printer driver, and restart the process. With some printers, you might need to connect the printer to your Windows computer to install the driver. After the driver is installed, you can disconnect the printer, delete the printer, and reconnect the printer to your Raspberry Pi. You can then follow these instructions to install the printer as a network printer.

Connecting to a Samba Print Server with MacOS (OSX)

Connecting to a Samba print server with MacOS (OSX) is a lot simpler than it is in Windows:

  1. Click System Preferences (Figure 6-17)

    A440135_1_En_6_Fig17_HTML.jpg
    Figure 6-17. Opening System Preferences

  2. Click Printers and Scanners

  3. Click the + (Plus) sign in the Printers window (Figure 6-18)

    A440135_1_En_6_Fig18_HTML.jpg
    Figure 6-18. Selecting the printer hosted on the Raspberry Pi

  4. Click the printer attached to the Raspberry Pi

  5. Configure the printer (Figure 6-19)

    A440135_1_En_6_Fig19_HTML.jpg
    Figure 6-19. Configuring the printer

Installing and Configuring SANE

Most printers are actually multifunction devices (print, scan, copy, etc.). To enable a Raspberry Pi to be used as a scanner server (using the scanner function of the device, or a dedicated scanner), install SANE (Scanner Access Now Easy):

sudo apt-get update              
sudo apt-get install sane

To determine if your scanner is detected, run sane-find-scanner:

sudo sane-find-scanner

Figure 6-20 illustrates the output from my system. It’s normal, by the way, for this command to find other USB devices, such as a USB wireless adapter. Note the location of the scanner (libusb:001:007). We will need to use this information later to complete scanner setup.

A440135_1_En_6_Fig20_HTML.jpg
Figure 6-20. Using sane-find-scanner to locate the installed scanner or multifunction device

To determine if scanimage (the scanning utility built into SANE) can use the scanner, run

sudo scanimage -L

Available scanners are identified (Figure 6-21).

A440135_1_En_6_Fig21_HTML.jpg
Figure 6-21. Using sudo scanimage -L to locate available scanners. The Epson all-in-one device is available via the network, and the HP Officejet is connected to the Raspberry Pi via a USB port.
Tip

If scanimage -L detects two or more scanners (see Figure 6-21), edit the dll.conf file used by SANE to support scanners: sudo nano /etc/sane.d/dll.conf. Place a # in front of the scanner brand(s) that you do not want to use. After saving your changes and exiting, run sudo scanimage -L again. This time, only one scanner should be listed.

To test the scanner , insert a document or photo and use one of the following commands:

  • sudo scanimage >test.tiff (this creates a TIF file that can be used with Windows, MacOS/OSX, and Linux apps)

  • sudo scanimage >test.pnm (this creates a file that can be used by the open source GIMP image editor)

Configuring SANE as a Server

To configure SANE to run as a server, we need to edit two files that control how SANE works, saned and saned.conf:

Edit saned with sudo nano /etc/default/saned

  • Change Run=No to Run=Yes[This enables saned to run automatically].

  • Make sure Run_As_User=saned is present and not commented out.

  • Save changes and exit.

Edit saned.conf with sudo nano /etc/sane.d/saned.conf

  • Add the following line to enable any device on your local network (assumes default gateway/router is at 192.168.1.1) to connect to the scanner:

    • 192.168.1.0/24

  • Save changes and exit.

Next, use an ls -l command to determine the ownership of the 007 file used by the scanner (Figure 6-22):

A440135_1_En_6_Fig22_HTML.jpg
Figure 6-22. Determining the ownership of the 007 file used by the HP OfficeJet multifunction device
sudo ls -l /dev/bus/usb/001

The output shows that 007 is owned by the lp group. To add a user to that group, use the adduser command :

sudo adduser saned lp

[or sudo usermod -a -G lp saned]

To enable and restart the saned.socket unit, use these commands:

sudo systemctl enable saned.socket              
sudo systemctl restart saned.socket

Reboot the system with sudo reboot after making these changes .

Connecting to SANE from Windows

There are several scanner apps available for Windows that support SANE scanners on a network:

SaneTWAIN was designed for 32-bit versions of Windows, but will run in 64-bit versions of Windows. To get it to run, use the following compatibility settings: Windows XP Service Pack 2, Run as Administrator.

SANEWinDS supports a wide variety of output file types, but it does not offer a preview mode for selecting photo size dynamically. If you don’t like the original scan, you must perform an additional scan after making changes.

xSANE Win32 has not been updated for several years, and works with scanners that are supported by standard SANE backends. It does not support scanners or all-in-one units that rely on additional software , such as HP.

SwingSANE uses JAVA to connect to SANE backends on other devices. It does not require scanner drivers to be configured on the client PC.

Connecting to SANE from MacOS (OSX)

MacOS supports SANE scanners hosted on Raspberry Pi or other Linux devices using third-party SANE-TWAIN for MacOS X ( www.ellert.se/twain-sane/ ; see https://macmanus.nl/2015/11/10/fixed-use-unsupported-scanner-in-osx-10-11-el_capitan/ for installation order and other help). SwingSANE can also be used with OSX (MacOS).

Unfortunately, Linux-hosted all-in-one devices are detected by Printer and Scanner preferences as printers because of the CUPS driver used to share the device.

SANE’s standard list of scanners is very outdated. If MacOS were a true Linux distro, you could install Linux multifunction drivers available from HP (HPLIP), Epson, and so on. Unfortunately, MacOS is not Linux, although it uses a Linux-like terminal interface that supports many Linux commands.

If you need access to the scanner on an all-in-one (multifunction) device on a network that includes Linux, Windows, and MacOS (OSX) devices, consider using a MacOS or Windows computer as the host.

Headless Boot

If you plan to use your Raspberry Pi as a dedicated print/scan server, you want it to be as inconspicuous as possible. Ditching the display, mouse, and keyboard and using SSH for remote access and headless booting enables you to put the Pi anywhere it can be powered. You can use raspi-config to set up your Raspberry Pi:

  1. sudo raspi-config

  2. Select Advanced options

  3. Select SSH

  4. Enabled? <Yes>

  5. <OK>

  6. <Finish>

Connecting via SSH Using Windows

To connect with your Raspberry Pi via SSH, you can use browser-based extensions such as FireSSH (Firefox), Secure Shell for Chrome, a Windows GUI such as PuTTY, or a command-line app (Cygwin). PuTTY is the most often-recommended Windows utility, and it is the app we use in this chapter.

Note

To learn more about using SSH in Windows, see www.makeuseof.com/tag/4-easy-ways-to-use-ssh-in-windows/ .

PuTTY is available from www.chiark.greenend.org.uk/~sgtatham/putty/latest.html . It’s available in 32-bit or 64-bit Windows versions as well as a UNIX archive. If you prefer to choose the components you like, the SSH and Telnet, SCP, SFTP, and other PuTTY components can also be downloaded separately.

To connect to a remote computer (such as your Raspberry Pi) using PuTTY:

  1. Start PuTTY

  2. Enter the IP address for the remote computer

  3. Make sure SSH is selected as the connection type

  4. Click Open (Figure 6-23)

    A440135_1_En_6_Fig23_HTML.jpg
    Figure 6-23. Preparing to log into a Raspberry Pi with PuTTY

After making the connection , enter the username and password you use for the Raspberry Pi (Figure 6-24).

A440135_1_En_6_Fig24_HTML.jpg
Figure 6-24. Logging into the Raspberry Pi via SSH

Troubleshooting

If you cannot connect to a printer share remotely:

  • Make sure the Raspberry Pi has a working network connection with ifconfig

  • Make sure the Raspberry Pi is in the same workgroup as the computer you are connecting from

  • Make sure you have entered the correct IP address and port number to open CUPS on the Raspberry Pi

  • Make sure CUPS has been configured to permit network connections

  • Make sure Samba has been installed and is properly configured

  • Make sure you have installed the correct drivers on your client system

If you cannot find a printer driver you can use with CUPS :

  • Make sure you have installed the correct drivers for use by CUPS

  • If you have drivers for similar models, try a similar model’s driver, perform a test print, and see if it works

If you cannot find a scanner driver you can use with SANE :

  • Make sure you have installed the correct drivers for use by SANE

  • If you have drivers for similar models, try a similar model’s driver, perform a test scan, and see if it works

If you cannot connect to SANE remotely:

  • Make sure you have installed the drivers needed to connect to SANE on your computer (varies by SANE helper app)

Summary

Almost all printers, scanners, and multifunction devices connect via USB ports. You might need to add a USB hub to your Raspberry Pi if it doesn’t have an available USB port. Following are additional tasks covered:

  • Use a GUI-less (command-line) distro such as Raspbian Jessie Lite and install it to a hard disk.

  • You might need to manually configure your Raspberry Pi to use a wireless connection.

  • Use CUPS to configure your printer or multifunction device’s print features.

  • If CUPS does not have built-in support for your printer or multifunction device, search for and install a suitable printer driver.

  • Use Samba to enable your Raspberry Pi to receive print and scan jobs.

  • To connect to your printer with Windows, use View Devices and Printers (Windows 7) or Settings (Windows 8.1/10).

  • To connect to your printer with MacOS (OSX), use Printer and Scanners from System Preferences.

  • Use SANE to configure your scanner or multifunction device’s scanner features.

  • You can choose from a variety of Windows and MacOS (OSX) scanner apps to access a scanner controlled by SANE.

  • Enable SSH if you want to boot your Raspberry Pi without a keyboard or display.