22-05-2012, 05:36 PM
DESIGN OF MONITOR-AND-CONTROL SYSTEM FOR SUPERMARKET FRESH AREA BASED ON ZIGBEE
ABSTRACT
According to the status that most of supermarkets can't effectively monitor the temperature and humidity around food of fresh area in our country Currently, the thesis designs a hierarchical topology central monitoring system based on ZigBee wireless sensor network (WSN). In the system, the temperature and humidity of surveyed area can be automatically monitored and controlled.
The monitoring nodes, with the CC2430 chip and THS11, can collect and upload temperature and humidity data to the Management Centre, which displays and processes the data, through the central node and the RS-232 interface. If the collected data exceeds the threshold, it automatically starts the alarm system and the regulating system; while the data is lower than the standard value, regulating system could be automatically shut down. Nodes work in the regular query power saving mode.
Power is obtained from button cells conversion through MAX687. The results reveal that this WSN system has the potential for field applications due to its low cost, low power and flexible networking construction.