Integrating RFID Transponders as Data Loggers in Wireless Sensor Nodes for Outdoor Remote Monitoring Operations

In this paper the integration of an RFID system into a wireless sensor node based on an Arduino board is discussed. The main purpose of the proposed solution is to use the memory of a passive RFID transponder to store the data retrieved by the sensors composing the node. This solution can be employed for remote monitoring operations, when no connection is available and then no remote data collection is possible. The RFID transponder allows the storage of a large number of sensor data sets, that can be then acquired simply removing the transponder from the node and reading it with a common desktop reader. Once collected, the transponder is replaced with a new one allowing a new period of data collection regardless of human intervention. An ad-hoc data structure has been studied to optimize the memory usage and then to increase the life time of a single transponder. The solution is especially thought for outdoor monitoring operations: contactless data transfer allows the sensor node to be sealed and then to be totally protected from atmospheric agents.