基于LoRa的农田信息无线采集方案设计

针对传统的农业WSN存在距离近、功耗高的问题，提出一种基于LoRa技术的农田信息无线采集系统。通过分析无线网络构成，给出了网络参数的设计原则，优化网络结构、降低组网难度、提高组网效率。选择以STM32L053处理器、SX1276无线芯片和SHT11温湿度传感器组成精简的低功耗节点硬件电路。设计了低功耗、低碰撞的星型无线网络结构，该系统采用分时方法周期性地对传感器数据进行采集和发送。通过实验分析了节点的功耗，时隙长度的选择，对包接收率和接收信号强度指示(RSSI，received signal strength indication)的关系进行研究。结果表明该系统具有通用性强、功耗低、距离远、组网便捷、稳定可靠等特点，能够满足农田信息采集的应用需求。

Design of field information wireless acquisition scheme based on LoRa

Aiming at the problems of traditional agricultural WSN such as short distance, high power consumption. A field information wireless acquisition system based on LoRa technology was proposed. By analyzing the composition of the wireless network, the design principles of the network parameters were given, the network structure was optimized, the networking difficulty was reduced, and the networking efficiency was improved.Choosing STM32L053 processor, SHT11 digital temperature and humidity sensor and SX1276 wireless chip to form a compact low power node hardware circuit. A low power and low collision star wireless network structure was designed. This system periodically collected sensor data through time-sharing sampling method. The node''s power consumption and the selection of time slot length as well as the relationship between packet reception rate and RSSI (Received Signal Strength Indication) were analyzed by experiment. The results show that the system has the characteristics of strong universality, low power consumption, long distance, easy networking, stable and reliable, which can meet the application demand of field information acquisition.