Raspberry Pi next to a printer

How to Turn a USB-Only Scanner into a Wireless Scanner Using SANE and a Raspberry Pi

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Intro

This post builds on the work I started in the last article where I turned our USB-only printer into a wireless printer. I recently figured out how to set the same printer/scanner to scan documents wirelessly. In this post, I’ll show you how to do it using the SANE utility. SANE stands for Scanner Access Now Easy.

Install SANE

# install
sudo apt-get install sane-utils

Configure the SANE daemon

Find and edit the SANE configuration file:

# Edit the configuration file
sudo nano /etc/sane.d/saned.conf

In it, add the IP addresses of the computers that should be allowed to scan over the network. Look for a section that looks like this and add the IP addresses or address ranges here:

## Access list
# A list of host names, IP addresses or IP subnets (CIDR notation) that
# are permitted to use local SANE devices. IPv6 addresses must be enclosed
# in brackets, and should always be specified in their compressed form.
#
# The hostname matching is not case-sensitive.

#scan-client.somedomain.firm
#192.168.0.1

Make sure to remove the # in front of the IP address you want to add.

Restart the Daemon

sudo systemctl restart saned.socket

Test the setup

Run the following commands to find and list scanners connected to your computer

# Find scanners
sane-find-scanner

# List scanners
scanimage -L

Use

Do this to run the command on the Pi and save the result locally

ssh user@pi scanimage > image.jpg --format jpeg

Scan over network

To scan over the network, install a frontend to SANE like scanservjs

Install it

The command below runs the install script that downloads a .deb file and installs it with apt

curl -s https://raw.githubusercontent.com/sbs20/scanservjs/master/bootstrap.sh | sudo bash -s -- -v latest

To uninstall

sudo apt-get remove scanservjs

Configure reverse proxy

Make the scanservjs server accessible in your local network by placing it behind a reverse proxy. Here’s an example using Nginx. Create a new virtual host in /etc/nginx/sites-available/scanservjs. Replace scanner.vuyisile.lan with your own domain

server {
    # increase timeouts since scan operations can take some time
    server_name scanner.vuyisile.lan;
    proxy_read_timeout 300;
    proxy_connect_timeout 300;
    proxy_send_timeout 300;

    location /scanner/ {
        proxy_set_header X-Real-IP $remote_addr;
        proxy_pass                 http://127.0.0.1:8080/;
    }
}

Enable it

sudo ln -s /etc/nginx/sites-available/scanservjs /etc/nginx/sites-enabled/

Scan

In your browser, go to http://scanner.vuyisile.lan (replace with the domain you chose) to scan. You’ll see a UI like the one in the picture below.

Scanservjs User Interface