NFC Tag Reader Simulator

Features

• grants or denies tags depending on UID
• can enroll dynamically a new tag (becoming granted)
• alarms after 3 fails in 5 minutes (configurable)

Ideas of future features

• online verification (use wifi to call an HTTP API to get the decision for the UID read)
• host a Web GUI providing poweroff, adding/removing a tag

Pre-requisite

Pi Zero

Raspberry Pi OS Debian 11+.

As user pi:

sudo apt-get install python3 python3-venv
#sudo systemctl mask [email protected]   # it appears it was not needed
mkdir ~/nfc_tag_reader_simulator
cd ~/nfc_tag_reader_simulator
python3 -m venv venv
source venv/bin/activate
pip install -r requirements.txt

If not inside a venv:

sudo apt-get install python3-smbus
sudo pip install -r requirements.txt

Additional since Debian 12:

sudo apt install libopenjp2-7

Arduino (Nano) + NFC module

MFRC522

Flash nfc_module/nfc_module.ino if you have an Arduino + MFRC522 (based on https://github.com/ElRojo/MiSTerRFID/blob/main/arduino/misterrfid.ino)

Change the value of WRITE_TAG if you want to have a master key to authorize additional tags.

Don't forget you can adjust the gain by editing the line:

    rfid.PCD_SetRegisterBitMask(rfid.RFCfgReg, (0x02<<4)); // RFID Gain

Note: for our RobotDyn MFRC522, we have set 0x02<<4 (otherwise, it had the tendency to read incorrect values sometimes).

How-to flash with arduino-cli from the raspberry pi (as user pi):

cd
curl -fsSL https://raw.githubusercontent.com/arduino/arduino-cli/master/install.sh | sh
sudo ln -s ~/bin/arduino-cli /usr/local/bin/
arduino-cli config init
arduino-cli core update-index
arduino-cli core install arduino:avr
arduino-cli core list
=> Check that "Arduino AVR" is listed
arduino-cli board list
=> Check that "/dev/ttyUSB0" is listed
arduino-cli lib install "Easy MFRC522"
arduino-cli compile -b arduino:avr:nano nfc_module/
arduino-cli upload -b arduino:avr:nano --port /dev/ttyUSB0 nfc_module/
=> Check that it displays "New upload port: /dev/ttyUSB0 (serial)"

PN532

Flash nfc_module_pn532/nfc_module_pn532.ino if you have an Arduino + PN532. Note: the PN532 libraries used were committed into this project because they included messages printed on serial port, which would break our code reading the serial.

Crontab

crontab -e

With venv

@reboot while true; do ~/nfc_tag_reader_simulator/venv/bin/python ~/nfc_tag_reader_simulator/nfc_tag_reader_simulator.py; sleep 10; done

Without venv

@reboot while true; do python ~/nfc_tag_reader_simulator/nfc_tag_reader_simulator.py; sleep 10; done

Modules

Touch pHat (optional)

Plugged on GPIO pins.

LEDs (optional)

Plug LEDs:

• a red LED on GPIO17 (pin 11)
• a green LED on GPIO27 (pin 13).

Buzzer (optional)

Plug the buzzer on GPIO22 (pin 15).

OLED screen (optional)

Follow install instructions on https://github.com/mklements/OLED_Stats

Plug SSD1306:

• OLED VCC on 3V3 (pin 1 on Pi Zero)
• OLED SDA on SDA1 (pin 3)
• OLED SCL on SCL1 (pin 5)
• OLED GND on GND (pin 9)

POC result