The MFRC522 is an RF Module that consists of an RFID reader, RFID card and a key chain. The module operates 13.56MHz and supports 3 types of interfaces: SPI, UART and I2C. For example using I2C interface will allow you to connect plenty of RFID devices on just 2 wires. Learn More
PoE (Power over Ethernet) - is a technology that allows you to transfer power and data through a single Ethernet cable. All that is required is to connect a PoE-issuing device to a PoE-powered device via an RJ-45 network connector. Paired with a controller board, this module will allow you to power your project via Ethernet.