A step counter service for Java-enabled devices using a built-in accelerometer

The presence of 3D acceleration sensors in mobile devices has already raised a new range of context-aware applications, in particular in the sports and wellness sector. In this paper, we present an accelerometer-based step counter middleware for J2ME-enabled smartphones to simplify the development of activity aware applications, creating an abstraction layer between the client and the signal processing algorithms and raw sensor access. The service provides information about the step count, stop detection and changes in the phone's orientation, independently of the phone's location on the human body. The software package runs natively on Symbian S60 phones, providing an interface to J2ME applications and has been validated experimentally on a Nokia's N95 smartphone.