Pi Zero W – Wireless Pen Drive

Currently I am using this with my Elegoo Mars MSLA 3d printer. I am able to transfer files via network share and then after 10 seconds the files will show up in the print menu.

Start with installing raspbian light and setting up your wifi and ssh access. Instructions on how to do this.

Enable usb driver

Next, we need to enable the USB driver which provides the gadget modes, by editing two configuration files.

sudo nano /boot/config.txt

Scroll to the bottom and append the line below:


Press CTRL+O followed by Enter to save, and then CTRL+X to quit.

sudo nano /etc/modules

Append the following lines, just after the i2c-dev line:


Press CTRL+O followed by Enter to save, and then CTRL+X to quit.

Now shut down the Pi Zero W with the command:

sudo reboot

Create a container file

To enable mass storage device mode, we need to create a large file to act as the storage file on the SD card.

If you would like to change the size of the “usb drive” that shows up then change the 2G to something else. I personally have it as 8G on a 16gb pen drive:

sudo fallocate -l 2G /piusb.bin

We now need to format the file as a FAT32 file system so that the device can understand it. Enter the command below:

sudo mkdosfs /piusb.bin -F 32 -I

Mount the container file

Create a folder on which we can mount the file system:

sudo mkdir /mnt/usb_share

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

sudo nano /etc/fstab

Append the line below to the end of the file:

/piusb.bin /mnt/usb_share vfat users,umask=000 0 2

Press CTRL+O followed by Enter to save, and then CTRL+X to quit.

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

sudo mount -a

Install and configure Samba

The next step is to provide network access to the /mnt/usb_share folder that we created earlier. Run:

sudo apt-get update


sudo apt-get install samba winbind -y

When the installation is complete, we need to configure a Samba network share. For simplicity, this will not require a user name or password, as it is already protected by your wireless network security. If you want more security, see wiki.samba.org.

sudo nano /etc/samba/smb.conf

Scroll down to the end of the file and append the lines below:

browseable = yes
path = /mnt/usb_share
guest ok = yes
read only = no
create mask = 777

Press CTRL+O followed by Enter to save, and then CTRL+X to quit.

Now restart the Samba service for the changes to take effect:

sudo systemctl restart smbd.service

Automate USB device reconnect

In order for any changes we’ve made over the network we need to trigger a removed and reinserted event.

We can use a Python library called watchdog (magpi.cc/2sLL1fi), which is designed for monitoring file system events and responding to them. Install this with the command below:

sudo apt-get install python3-pip -y

Then run:

sudo pip3 install watchdog

The following script is not mine but does a very good job. Run the following commands:

cd /usr/local/share

Then run:

sudo wget https://raw.githubusercontent.com/hcker2000/usbpizw/master/usbshare.py -O usbshare.pysudo chmod +x usbshare.py

Background service

We need to make this program into a background service, so that it starts automatically at boot time. We can do that by making it into a systemd unit. Enter the commands below:

cd /etc/systemd/system

Then run:

sudo nano usbshare.service

This will start a new blank file. In the new file, enter:

Description=USB Share Watchdog

Press CTRL+O followed by Enter to save, and then CTRL+X to quit.

Now we need to register the service, enable it, and set it running:

sudo systemctl daemon-reload

sudo systemctl enable usbshare.service

sudo systemctl start usbshare.service