Processors have become multi-core, and transactional memory has been getting attention as a new concurrency control and coordination mechanism for shared data in this type of processor. Transactional memory is a memory management technology based on transactions used in the field of databases. An atomic action provided by transactional memory is a very effective programming abstraction not only for concurrency process control but also for system recovery. However, the previous research on transactional memory in an embedded system requires dedicated processor with hardware-assistance, not a generic middle-range or lower processor, mostly for concurrency control. In order to deploy transactional memory into embedded systems more widely, for a generic middle-range or lower processor without hardware-assistance we developed a transactional memory system for embedded systems from sensor and controller nodes to consumer electronics (STEM). Moreover the purposes of STEM are not only for shared data access control but also for partial recovery of the system. We designed and implemented an STEM prototype, and we demonstrate that the design and implementation is effective in practical usage.