Explaining how RFID works and the MFRC522 reader module, which runs on 3.3V logic over SPI, plus reading a card's ID from Arduino.
Prepare Raspberry Pi for sensors with correct 3.3 V GPIO logic, model-specific power, I²C or SPI setup, level shifting, and safe shutdown.
Update Raspberry Pi OS safely with APT, understand full-upgrade, avoid routine experimental firmware, and plan major-version migrations with backups.
Install Raspberry Pi OS with the official Imager, safely select boot media, preconfigure accounts, Wi-Fi, and SSH, then complete first boot.