Detecting Gas Pump Card Skimmers: A Raspberry Pi Dashboard Scanner

Build a Real‑Time Dashboard Gadget to Detect Card Skimmers at Gas Stations

Credit‑card fraud remains a pervasive threat, especially at gas stations where magnetic‑stripe cards are vulnerable to simple, inexpensive skimmer devices. A skimmer sits over the card slot, records the data, and forwards it to the pump’s point‑of‑sale system—essentially a “man‑in‑the‑middle” attack.

In 2023, SparkFun Electronics’ Nathan Seidle published a thorough analysis of stolen skimmers from fuel pumps and released a companion Android/iOS app that scans for the unique Bluetooth signatures of those devices. While useful, many users prefer a permanent, ambient solution that continuously watches for suspicious devices.

1. Hardware

Two components make up this kit: a Raspberry Pi Zero W and an Adafruit SSD1306 OLED display. The OLED supports both I²C and SPI; we’ll use SPI for faster data transfer. Wire the display according to the official SparkFun wiring guide. Keep cables short and flexible—28‑gauge solid or stranded wire works well.

2. Setting Up Raspbian

For a clean headless install, use Pi Bakery to bake a Raspbian image pre‑configured for your home network and SSH access. This eliminates the need for a monitor and keyboard during setup.

3. Installing Python and Libraries

sudo apt update
sudo apt install -y python3 python3-pip python3-dev bluetooth libbluetooth-dev git
sudo pip3 install pybluez
sudo pip3 install RPi.GPIO
sudo pip3 install Adafruit_BBIO
sudo apt install -y python3-imaging python3-smbus

Clone and install the SSD1306 driver:

git clone https://github.com/adafruit/Adafruit_Python_SSD1306.git
cd Adafruit_Python_SSD1306
sudo python3 setup.py install

4. Skimmer‑Scanner Software

Clone the open‑source scanner:

cd ~
git clone https://github.com/photoresistor/raspi_skimscan
cd raspi_skimscan
python3 raspi_skimscan.py

You’ll see a “Scanning…” message that updates every 10 seconds. To test, rename your phone’s Bluetooth device name to HC‑05—the scanner should flag it as a potential skimmer.

Make the script executable and configure it to start on boot:

sudo chmod +x raspi_skimscan.py
sudo nano /etc/rc.local

Insert the line before exit 0:

sudo python3 /home/pi/raspi_skimscan/raspi_skimscan.py &

5. Assembly

Download the enclosure files from the GitHub repo and 3D‑print them. Mount the OLED on the top plate, secure with a light touch of hot glue if desired, and position the Pi on the bottom plate. Fasten the halves together with M2.5×10 mm cap‑head screws.

Attach the finished unit to your vehicle’s dashboard or console where it’s visible but not distracting. Power it from any 5 V USB source capable of delivering at least 1 A.