Wireless sensor/actuator device configuration by NFC

In the area of building automation, many sensor or actuator devices are tiny embedded systems which are installed throughout the building. The sensors gather information about the current environment (e.g., the temperature, number of people in a room, etc.) and the actuators interact with the environment (e.g., controlling lights, heating, or door access). A central unit controls these devices (wirelessly or by wire), therefore all devices need at least a unique id throughout the system, and in many cases some more configuration or authentication data. New or replaced devices have to be registered with the central unit in order to enable correct control. Thus, the person installing a new device has to prepare it in terms of at least setting an id before it can be connected to the network. This can be tedious work, especially for untrained workers. This paper proposes adding an NFC module as an enhancement for standard devices. The devices can then be configured on site using a standard smart phone running an appropriate application. This eliminates the need to pre-configure devices using a programmer tool. The presented application enables (first-time or re-) configuration of wireless embedded devices. The prototype features an ATmega 328P micro-controller from Atmel and a M24SR02-Y NFC chip from STMicroelectronics.