Temperature and humidity wireless sensing and monitoring systems applied in greenhouse

Crop production in greenhouses is an increasing industry in the fields of agriculture. And greenhouse with all measures of environmental controlling and monitoring is some of the important component for crop production and protection. As you know, the most important variables in a greenhouse are temperature and relative humidity. This paper proposes a new different method aims at sensing and monitoring the temperature and humidity in greenhouse environment for different distance. The network structure used in this paper is star topology. It consists of one more sensor nodes, some repeat nodes, one main node, PC Terminal, MYSQL, web service and one real time alarm system. Based on this system, the circumstance parameters can be sensed and monitored. Once the alarm system monitors the parameters curve displays abnormally, the alarm system will inform the monitor to take some actions. Compared with the other previous proposed system, the advantage is that the sensing distance can be set as the user requirement. Although the wireless transceiver distance is limited by the battery power and it is just 1.26m, the distance can be enlarged for each node increasing 1.26m. And the total distance can be calculated as 1.26m×[1+N(Repeat Nodes)]. As the experiment results showed, this system holds low power dissipation, simple network distribution, and easy to maintain.