RATFAT: Real-Time FAT for Cooperative Multitasking Environments in WSNs

Today, many sensor nodes are equipped with a microSD slot to provide a cost effective way to store large amounts of data. When using the FAT file system, data collected by a node can be easily read by a PC without the need for any special software or communication protocol. While several FAT implementations for microcontrollers do exist, they are not suited for real-time applications. For a WSN in an industrial scenario where a node needs to run a closed loop control program, logging to a non-real-time capable persistent storage system is not an option. In this paper we present RATFAT, an efficient implementation of a flexible real-time capable FAT file system for Contiki, that can be used for applications requiring real-time guarantees.