Wireless Sensor Networks (WSNs) allow applications to interact with the physical world using sensing nodes deployed in an Internet of Things (IoT). Many WSN sensing nodes have constrained computing and memory capabilities. This paper details a new cache algorithm suitable for use on constrained nodes and its use in an architecture incorporating caching and the flow of data from sensors to services, possibly Cloud-based. This cache algorithm is influenced by the Clock paging algorithm and manages the leases of cached data in its replacement policy, removing the need for a separate process for this. This paper presents implementations of the algorithm in C on the Contiki OS and Java, compares its performance to LRU and considers its suitability for use on constrained WSN nodes.