Sensing the state of the environment is an important source for context-aware applications. Several approaches exist to provide sensor information to mobile application nodes. As the extreme cases we have pure infrastructures and pure ad hoc networks. In order to allow sensor platforms to serve both of these approaches, we have designed a universal sensor platform and integrated it into an infrastructure-based approach as well as into ad hoc networks. In this paper we discuss the requirements on such a platform, the design, and the experiences.