Introduction
The E52-400/900NW22S is a wireless serial LoRa MESH networking module based on LoRa spread spectrum technology. It features a maximum output power of +22 dBm, a maximum air data rate of 62.5K, and a maximum supported baud rate of 460800 bps. The E52-400NW22S module operates in the frequency range of 410.125 ~ 509.125 MHz (default 433.125 MHz), while the E52-900NW22S module operates in the frequency range of 850.125 ~ 929.125 MHz (default 868.125 MHz). The module adopts a new LoRa MESH networking technology with features such as decentralization, self-routing, network self-healing, and multi-level routing, making it suitable for applications including smart home and industrial sensors, wireless alarm security systems, building automation solutions, and smart agriculture. The LoRa MESH network adopts a decentralized architecture, where the entire network consists of only two types of nodes — end nodes and routing nodes — with no central node or coordinator required for network management. Users can also build a MESH network using routing nodes exclusively. Routing nodes are similar to end nodes, except that end nodes lack routing capability. End nodes are typically deployed at the network edge and are commonly used to design low-power nodes; however, low-power functionality is not currently supported. Routing nodes must continuously receive network data for route updates and data forwarding, and therefore cannot be used as low-power nodes. The MESH network employs CSMA collision avoidance technology, a mechanism designed to prevent nodes from transmitting wireless data simultaneously, thereby reducing the probability of data collision errors. Routing nodes automatically collect information from surrounding nodes to form a multi-hop communication network; when a link fails or becomes abnormal, routing nodes re-establish new paths after multiple consecutive communication failures. The network supports four communication modes: unicast, multicast, broadcast, and anycast, allowing users to select the appropriate mode based on different application scenarios. Among these, unicast and broadcast are the simplest and most fundamental communication modes. In unicast mode, routes are automatically established and request responses are returned to determine the data transmission path; in broadcast mode, all routing nodes initiate data relay upon receiving data. The multicast mechanism is relatively more complex.
