Among them, sensors (temperature sensor, humidity sensor, PH value sensor, illuminance sensor, CO2 sensor) are the key components of the agricultural Internet of Things.

The Internet of Things is based on the computer Internet, using RFID, wireless data communication and other technologies to construct an "Internet of Things" covering everything in the world. In this network, items (commodities) are able to "communicate" with each other without human intervention. Its essence is to use radio frequency automatic identification (RFID) technology to realize the autom···

Five key technologies of the Internet of Things The foundation of the future Internet of Things industry Long-range wireless network communication technology

The cellular-based Narrow Band Internet of Things (NB-IoT) has become an important branch of the Internet of Everything. NB-IoT is built on a cellular network and only consumes about 180KHz of bandwidth, and can be directly deployed on a GSM network, UMTS network or LTE network to reduce deployment costs and achieve smooth upgrades.

NB-IoT user terminals can work in power saving mode to reduce power consumption and prolong battery life. When the user terminal works in the power saving mode, similar to the shutdown of the device, it seems to be disconnected from the network, but the user terminal is still registered in the network and does not need to re-attach or re-establish a packet data network (Packet Data Network) connec···

As the most promising low-power wide-area communication technology, LoRa has been used in all walks of life. LoRa uses linear frequency modulation spread spectrum modulation technology, which maintains low power consumption, significantly increases communication distance and network efficiency, and eliminates interference, so that even if the same frequency is used for simultaneous transmission, t···

Compared with GPRS, the biggest feature of NB-IoT is low power consumption. In addition to the relatively low transmission rate of NB-IoT itself, NB-IoT introduces eDRX power saving technology and PSM power saving mode, which is also the main reason for power saving.

NB-IoT is a new narrowband cellular communication LPWAN (Low Power Wide Area Network) technology that can help us solve this problem.

The serial server is a serial port to Ethernet module plus a shell, which has the function of electromagnetic isolation.

The serial port server provides the serial port to network function, which can convert the RS-232/485/422 serial port into a TCP/IP network interface, and realize two-way transparent data transmission between the RS-232/485/422 serial port and the TCP/IP network interface. The serial device can immediately have the function of TCP/IP network interface, connect the network for data communication, a···