Dynamic tags open new NFC opportunities
The principle of dynamic tags consists of using a buffer where information can be written and read by two or more devices. The buffer can be the tag’s internal non-volatile EEPROM (or a volatile memory, if one is available). The buffer becomes a sharing point for an external device (a mobile for example) and a processor that also has access via a conventional serial interface (I2C being the most common from tags). This mechanism simulates bidirectional communication between the mobile and the processor.
The two-way communication capabilities of NFC Dynamic tags can turn mobiles into Human Machine Interfaces (HMI) for systems, equipment and appliances. Compared to Bluetooth Low Energy, or Wi-Fi, NFC offers advantages based on its very short range. However, all of this hinges on the mobile’s ability to write and to read data to tags.
NFC clearly does not fit every use case. However there are some specific cases that are, in particular enabled by NFC dynamic tags:
NFC secure pairing of Bluetooth or Wi-Fi
3-Stroke configuration of equipment via NFC
If you are going to use your mobile as an HMI for equipment and appliances, NFC is a secure and intuitive means for establishing a temporary, secure local connection with Bluetooth or Wi-Fi. NFC takes over and automates a series of actions in a way that is perfectly transparent for the user. With a simple gesture, NFC:
Launches the appropriate application on the mobile
Wakes up available Bluetooth or Wi-Fi channels (which start emitting advertising signals)
Authenticates and builds encryption keys for the session
Pairs the Bluetooth or Wi-Fi channel
Switches to the secured Bluetooth or Wi-Fi channel
These actions greatly facilitate and secure the implementation for the end-user. The disadvantage of "staying close" to communicate with NFC is replaced by the comfort offered by the increased range of Bluetooth or Wi-Fi. The complexities of setting up Bluetooth or Wi-Fi connections are reduced by NFC to a simple gesture that literally takes about 2 seconds.