Dual interface memory
An RFID transponder, which has a dual interface, offers the option of exchanging data between systems wirelessly via the RF interface, whereby there is often an I2C or SPI interface on the other side
From a purely technical point of view, this is a memory that has an RFID interface (e.g., as per ISO 15693) on one side and a microcontroller interface (in most cases I2C or SPI) on the other side. This means that it is possible to exchange a wireless or network code. When pairing two devices, for example when pairing a mobile phone in the car, if the mobile phone is held briefly at a predefined position in the car then the phone is identified and a code is exchanged that is then used for further communication via other (usually faster) interfaces. In this example, the actual communication of user data (phone, music streaming, etc.) is via the Bluetooth interface, while the RFID functionality with dual interface memory was only used to prepare the authentication phase of the Bluetooth connection.
In order to track PCBs or modules individually, each unit receives an individual serial number, which is stored in an RFID tag
If this RFID tag is a dual interface memory, then it is possible to communicate with the device via the transponder in order to enable functions, activate the device or read data such as the hardware/software status or the error memory. All that is needed is an RFID chip soldered directly on the board and an RFID antenna implemented as a conductive path. Unlike conventional dual interface products, which have more memory, PCB tracking is only used as a replacement for the barcode, however all production data can be stored on the RFID chip.