Wireless sensor networks equipped with rechargeable batteries are useful for outdoor environmental monitoring. However, the severe energy constraints of the sensor nodes present major challenges for long-term applications. To achieve sustainability, solar cells can be used to acquire energy from the environment. Unfortunately, the energy supplied by the harvesting system is generally intermittent and considerably influenced by the weather. To improve the energy efficiency and extend the lifetime of the networks, we propose algorithms for harvested energy prediction using environmental shadow detection. Thus, the sensor nodes can adjust their scheduling plans accordingly to best suit their energy production and residual battery levels. Furthermore, we introduce clustering and routing selection methods to optimize the data transmission, and a Bayesian network is used for warning notifications of bottlenecks along the path. The entire system is implemented on a real-time Texas Instruments CC2530 embedded platform, and the experimental results indicate that these mechanisms sustain the networks’ activities in an uninterrupted and efficient manner.

With development of internet and information technology, the traditional agricultural production cannot meet people's demand. The IoT (Internet of Things) technology is now taking this opportunity to modernize agriculture especially the greenhouse planting industry. This paper proposed a novel intelligent greenhouse cultivation system which not only liberate the farmers' labor force but also break constraints on disastrous weather shock, pest outbreak and other undesirable environment limitations. This system have been put into practice in southeastern China, including four functional parts, which are environmental parameters collection, data transmission, information processing, and data regulation and feedback control. These useful data acquired from IoT sensors were utilized to evaluate plant growth and predict the amount of liquid fertilizer to minimize waste of resources. Besides, a reliable PLC (Programmable Logic Controller) was adopted to enhance resistance to interference. Meanwhile, remote computers were adopted as a monitoring center to guarantee the flexibility of whole control system.