RFID stands for Radio-Frequency Identification — a wireless technology covering devices for security, access, and goods tracking purposes. In essence, an RFID system includes an RFID reader and one or more tags. Both hardware devices are contained in a versatile kit of parts aimed at Arduino experimenting and backed by a specially written guide. In this article, as an example of embedded project development from the ground up, Elektor guide author Dogan Ibrahim explores RFID technology and gets help from “our mutual friend,” the Arduino UNO.