基于LoRa技术的通用型环境监测节点低功耗设计

Low-power Consumption Design of a General-purpose Environment Monitoring Node Based on LoRa Technology

针对环境监测无线传感器网络节点兼容性不足、电池容量有限等问题,设计了一种基于LoRa技术的多传感器兼容型低功耗监测节点;节点底层提供丰富接口以及标准化封装,并采用结构体存储传感器操作信息、链表记录可读取的传感器,使节点兼容多种传感器,解决传感器适配问题;采用STM32L系列单片机和LoRa模块搭建硬件平台,提出了一种应用于LoRaWAN的自适应功耗算法,通过合理配置各模块休眠状态、优化LoRa发送功耗和空传速度等方法;经测试,该节点运行功耗1.22 mW,休眠功耗0.4 mW,无线传输过程节省能耗最高可达89.5%,有效延长了节点寿命;实验结果表明,该节点具有良好的可扩展性和低功耗特性,为无线传感器网络节点在智慧农业、智慧城市等领域的推广应用提供一定的理论方法和技术支持。

Aiming at the problems of the insufficient compatibility and the limited battery capacity of the existing wireless sensor network nodes in the field of environment monitoring,a multi-sensor compatible and low-power consumption monitoring node based on the LoRa technology is designed.In order to be compatible with many kinds of sensors,the rich interfaces and standardized packaging are provided in the physical layer.Meanwhile,the structures are used to store the sensor operation information,as well as linked lists are employed to record the readable sensors.To reduce the power consumption,a microcontroller of STM32L series and a module of LoRa are used to build the hardware platform,and an adaptive power consumption algorithm applied to the LoRaWAN is proposed.By properly configuring the sleep state of each module and optimizing the LoRa transmission power and the air transmission speed,the power consumption of the node is only 1.22 mW in operation and 0.4 mW in sleep.Furthermore,the energy consumption in the wireless transmission process can reduce by about 89.5%,which effectively prolongs the node life.The experimental results show that the node performs well in extensibility and lower power consumption,which provides some theoretical methods and technical support for the utilization of the wireless sensor network nodes in smart agriculture,smart city,as well as other fields.