Rasp-Pi Network ID tool

I needed a tool that could display relevant network information as quick as possible. Armed with a Raspberry Pi 3 B+, 2.13 inch Waveshare e-paper HAT V2, and a curiosity to explore its potential, I set out to develop a tool that could display network data. This was born out of necessity while I was setting up VLANs within PfSense. I got tired of using "ipconfig /release" and "ipconfig /renew" while testing network segregation and firewall rules. I will share that project in an additional post.

I plan making this post as concise as possible. During my research to make this project a reality, I dug through a lot of fluff to find the information I needed.

I assume you know how to flash the OS on to the PI. We will start post Pi imager. I used a fresh 64GB SD card. Also, noticed that the 128GB SD card I had initially used would not boot properly. I did not delve further to determine whether is was the SD card size or some operator error. Usually the latter..

pi@NetworkID:~ $ sudo apt update
pi@NetworkID:~ $ sudo apt upgrade

#install required packages
pi@NetworkID:~ $ sudo apt-get install python3-rpi.gpio python3-spidev python3-pil python3-pip

Next we will enable the SPI interface. We will do this from the raspi-config interface.

pi@NetworkID:~ $ sudo raspi-config

Choose option 3 - Interface options

Enable the SPI interface by selsecting the option. Then select finish when the main screen reappears.

pi@NetworkID:~ $ git clone https://github.com/waveshare/e-Paper.git
Cloning into 'e-Paper'...
remote: Enumerating objects: 8711, done.
remote: Counting objects: 100% (1961/1961), done.
remote: Compressing objects: 100% (264/264), done.
remote: Total 8711 (delta 1745), reused 1778 (delta 1694), pack-reused 6750 (from 1)
Receiving objects: 100% (8711/8711), 42.23 MiB | 307.00 KiB/s, done.
Resolving deltas: 100% (6242/6242), done.
Updating files: 100% (3002/3002), done.

Give it few seconds to clone the repository. When it has finished, navigate to the e-paper directory that was created and run setup.py

pi@NetworkID:~ $ cd e-Paper/RaspberryPi_JetsonNano/python/

pi@NetworkID:~/e-Paper/RaspberryPi_JetsonNano/python $ sudo python3 setup.py install

This is where I made a mistake. I needed to install Python3 Setup Tools and netifaces. These libraries are crucial for proper set up and network interface queries using python.

pi@NetworkID:~/e-Paper/RaspberryPi_JetsonNano/python $ sudo apt install python3-setuptools
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
python3-setuptools is already the newest version (66.1.1-1).
python3-setuptools set to manually installed.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

pi@NetworkID:~/e-Paper/RaspberryPi_JetsonNano/python $ sudo apt install python3-netifaces

Now lets try to run Setup.py again.
Now after we have all the libraries and configurations correct, let's write some code!

import subprocess
import netifaces
from waveshare_epd import epd2in13_V2
from PIL import Image, ImageDraw, ImageFont
from datetime import datetime

# Initialize e-Paper display
# Specifically for 2.13" V2 
epd = epd2in13_V2.EPD()

# Define fonts
font = ImageFont.truetype('/usr/share/fonts/truetype/dejavu/DejaVuSans-Bold.ttf', 12)
font_small = ImageFont.truetype('/usr/share/fonts/truetype/dejavu/DejaVuSans-Bold.ttf', 10)

def get_network_info(interface):
    try:
        # Get network information for the specified interface
        if interface in netifaces.interfaces():
            addresses = netifaces.ifaddresses(interface)
            ip_address = addresses[netifaces.AF_INET][0]['addr']
            netmask = addresses[netifaces.AF_INET][0]['netmask']
            gateway = netifaces.gateways()['default'][netifaces.AF_INET][0]
            mac_address = addresses[netifaces.AF_LINK][0]['addr']
            return ip_address, netmask, gateway, mac_address
        else:
            print(f"Interface {interface} not found.")
            return None, None, None, None
    except Exception as e:
        print(f"Error retrieving network information: {e}")
        return None, None, None, None

def get_ssid(interface):
    try:
        # Execute the iwgetid command to get the SSID of the specified interface
        result = subprocess.run(['iwgetid', interface, '--raw'], capture_output=True, text=True)
        if result.returncode == 0:
            return result.stdout.strip()
        else:
            return "SSID not found"
    except Exception as e:
        print(f"Error retrieving SSID: {e}")
        return "SSID error"

def display_network_info(ip_address, netmask, gateway, mac_address, ssid=None):
    # Create new image with white background (landscape orientation)
    image = Image.new('1', (epd.height, epd.width), 255)
    draw = ImageDraw.Draw(image)

    # Clear display
    epd.init(epd.FULL_UPDATE)
    epd.displayPartBaseImage(epd.getbuffer(image))

    # Draw network information on the display
    draw.text((10, 10), f"IP Address: {ip_address}", font=font, fill=0)
    draw.text((10, 30), f"Subnet Mask: {netmask}", font=font, fill=0)
    draw.text((10, 50), f"Default Gateway: {gateway}", font=font, fill=0)

    # Add timestamp
    current_time = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
    draw.text((10, 70), f"Timestamp: {current_time}", font=font, fill=0)

    # If SSID is available, display it
    if ssid:
        draw.text((10, 90), f"SSID: {ssid}", font=font, fill=0)

    # Display MAC address
    draw.text((10, 110), f"MAC Address: {mac_address}", font=font, fill=0)

    # Rotate the image 90 degrees clockwise
    image = image.rotate(90, expand=True)

    # Display rotated image on the e-Paper display
    epd.init(epd.FULL_UPDATE)
    epd.display(epd.getbuffer(image))

    # Sleep to conserve power
    epd.sleep()

def main():
    # Check for wireless connection first
    # Wirelss connection need to be configured before hand

    if 'wlan0' in netifaces.interfaces():
        interface = 'wlan0'
        ip_address, netmask, gateway, mac_address = get_network_info(interface)
        ssid = get_ssid(interface)
        if ip_address:
            display_network_info(ip_address, netmask, gateway, mac_address, ssid)
    # If no wireless connection, check for wired connection
    # Make sure the name of the interface here matches what is running on your device
    elif 'eth0' in netifaces.interfaces():
        interface = 'eth0'
        ip_address, netmask, gateway, mac_address = get_network_info(interface)
        if ip_address:
            display_network_info(ip_address, netmask, gateway, mac_address)
    else:
        print("No network interface found.")

if __name__ == '__main__':
    main()

I choose to use crontab to run this script at reboot.

pi@NetworkID:~ $ contab -e 

# Use option one, or whichever editor you'd like.
# At the end of the file add this line.

@reboot /usr/bin/python3 /home/pi/network_monitor.py

# This will run the script at each reboot.