Raspberry Pi Zero Wireless – Smart USB Flash Drive [Samba Server]

In this tutorial, I am going to show you how to configure the Raspberry Pi Zero Wireless as a smart USB flash drive. Typically, people use a USB flash drive to transfer files between different devices, but it takes time to move the drive to and from the source device. How about a remotely accessible USB flash drive, permanently located in the equipment, where you could transfer files using the wireless connection?

Before the procedure, here is a video with the SSH configuration if you want to see it in a graphic format.

Parts Required

• Raspberry Pi Zero Wireless

Procedure

Following are the steps required to perform this configuration.

Step 1 – Using the SD Card Formatter software, format the Raspberry Pi SD card to be used.

Step 2 – Download the Raspbian Jessie Lite iso image.

Step 3 – Using the Win32DiskImager software to install the Raspbian Jesie.

Step 4 – In order to automatically access a wireless network, it is necessary to create a file named wpa_supplicant.conf with the following configuration.

Step 5 – Create an empty file named ssh (without extension). For this, it is necessary to activate the following functionality in Windows:

Step 6 – Paste these 2 files on the Raspberry Pi SD card.

Step 7 – Insert the SD card into the RPi and power on via USB.

Step 8 – Via the PuTTY software, connect to the RPi via SSH.

Step 9 – Login with default credentials. Name: pi Password: raspberry

Step 10 – Adding the ssh file to the boot partition is only temporary, the file is removed at startup and ssh does not start on subsequent boots. Immediately after logging into SSH, it is necessary to activate ssh via raspi-config.

Step 11 – Clean up some disk space (performance increase).

sudo apt-get remove –purge libreoffice* -y
sudo apt-get purge wolfram-engine -y
sudo apt-get clean
sudo apt-get autoremove -y

Step 12 – Enable the USB Driver.

The USB port on the Pi Zero is directly connected to the processor, unlike other RPi’s that use an integrated USB hub. This cheaper solution means that the Pi Zero can be configured to act as a USB host, like a computer, a “USB device”, among others. To activate the “USB device” mode, some specific modules of the “dcw2” kernel must be activated. In this specific case, the required module is “g_mass_storage”.

Enable the DCW2 USB Driver

Open config.txt file: sudo nano /boot/config.txt

Add this text to the end of the file: dtoverlay=dwc2

Open modules: sudo nano /etc/modules

Add this text to the end of the file: dwc2

After that turn off the raspberry: sudo halt

Step 13 – Create storage file.

It is necessary to create a large file in order to act as a storage interface on the SD card. This file will emulate the USB flash drive that different devices see.

The command below will create an empty 2 GB binary file (change the count = 2048 parameter if you want a different size). This value is limited by the space available on the SD card and it may take a few minutes to complete the setup:

sudo dd if=/dev/zero of=/usb-drive.img bs=1M count=2048

It is now necessary to format the file as a FAT32 file system:

sudo mkdosfs -F 32 /usb-drive.img

Step 14 – Mount the storage file.

First, create a folder in which we can mount the file system:

sudo mkdir /mnt/usb_share

Now let’s add this to fstab, the configuration file that records the available disk partitions:

sudo nano /etc/fstab

Add the following line at the end of the file:

/usb-drive.img /mnt/usb_share vfat users,umask=000 0 2

The line we added to fstab allows the USB file system to be checked and mounted automatically at boot time. Instead of restarting, we can manually reload fstab with the command below:

sudo mount -a

Step 15 – Mass Storage Device Mode

The command below will activate the mass storage device mode:

sudo modprobe g_mass_storage file=/usb-drive.img stall=0 removable=1

At this moment, if the Raspberry Pi is connected via USB to a device such as a computer, the connection pop-up for a new storage device is given.

To unmount manually:

sudo modprobe -r g_mass_storage

Step 16 – Automatic Start

To run a program on your RPi at startup it is necessary to modify the bashrc file. With the .bashrc method, it is possible to execute commands at startup. Place the command at the bottom of ‘/home/pi/.bashrc’. The program can be aborted with ‘ctrl-c’ while it is running!

sudo nano /home/pi/.bashrc

Go to the last line of the script and add:

sudo modprobe g_mass_storage file=/usb-drive.img stall=0 removable=1

Restart the RPi: sudo reboot

Step 17 – Enable Auto Login

sudo raspi-config

Boot Options -> Desktop / CLI -> Console Autologin

Step 18 – Install and Configure Samba Server

Update Raspbian:

sudo apt-get update
sudo apt-get upgrade

Install Samba Server:

sudo apt-get install samba samba-common-bin

We will now create a shared folder that we will access later using Windows:

mkdir /home/pi/datafolder

Assign all permissions to the folder we just created:

chmod 777 datafolder

Now let’s edit the samba configuration file, to include the folder we just created:

sudo nano /etc/samba/smb.conf

Insert the lines below at the end of the file:

[RPi]
comment = RPi Share
path = /home/pi/datafolder
create mask = 0777
directory mask = 0777
writable = true
security = share
browseable = true
public = yes

Restart samba service: sudo service smbd restart 

Restart the RPi: sudo reboot

Step 19 – Access RPi from Windows

Find RPi IP command: hostname -I

References

[1] http://massimomusante.blogspot.com/2018/03/sharing-files-on-raspberry-pi-zero-w.html

[2] https://magpi.raspberrypi.org/articles/pi-zero-w-smart-usb-flash-drive

[3] https://magpi.raspberrypi.org/articles/samba-file-server

[4] https://gist.github.com/gbaman/50b6cca61dd1c3f88f41