Greenhouse Environment Intelligent Monitoring System

This paper introduces a multilevel Intelligent Environment Monitoring System of Greenhouse based on RS485 BUS technique, which performs real time measurement of temperature, humidity of the air, soil moisture and Carbon Dioxide concentration in the greenhouse. The administrator can monitor the environment conditions in the greenhouse by using it.The system adopts multilevel distributed structure and multi-CPU technique composed of the upper set, the mid-controller and the lower set. The lower set mainly fulfils the environment data collecting and processing. Then the data will be transmitted to the mid-controller through RS485 BUS. There is one mid-controller in each greenhouse that displays the data transmitted by the lower set in turn and gives off an alarm signal when the data is beyond the threshold value that was set by users. The upper set performs the mid-controller address setting, the mid-controller working condition inquiring and the threshold value of environment element setting and then achieves uniform management of all the greenhouses.Adopting multilevel distributed structure not only avoid the loss of analog signal caused by long-distance transmission, but also simplifies the wiring and facilitates adding the amount and sorts of sensors. The system is easy to be extended and upgraded.This paper brings forward a method to expand the UART of AT89C52 by using an AT89C2051, which performs the unattached communication between the mid-controller to the upper set and the mid-controller to the lower set.The paper completes both the software and hardware design and presents a kind of Intelligent Environment Monitoring System that can be applied to the greenhouse.