Taking advantages of off-the-shelf cloud platform services, rather than maintaining a private database for logging the data from sensors, can significantly reduce labor and equipment costs for using a reliable database system. In this study, we present an inexpensive (less than 30 USD) embedded gateway with mobile network connectivity that can talk directly to cloud storage service providers, such as Google Apps Engine (hereafter called GAE). This embedded gateway can be used to collect data from networked wireless sensors in the field. The proposed design is characterized by: (1) using mobile networks to upload collected data without the need to pre-deploy conventional network equipment in the field; and (2) using cloud platform services for the logging of data. We designed and implemented this framework and installed it in a test site to evaluate its performance. This gateway framework can facilitate the design of a sensor system for collecting on-site signals, leveraging the benefits of cost-effective, always-ready, and reliable data storage service.