Abstract: In this paper, we design a system to collect information in agriculture, which is based on wireless sensor networks. There is a hardware design of node using CC2430 at first, and then a system is built based on the actual application. In this system, nodes can collect data in three modes such as the mode of period collection, the mode of query on the fixed points and the mode of anomalies. Usually，nodes work in the mode of period collection, collect and send data to the coordinator in a fixed period, and the coordinator will send the data to a remote server to be stored or analyzed. When there is a special demand of query, users can send the command, which can make part of the network enter into the mode of query on the fixed points, and then the nodes concerned collect data at the fixed point. Additionally, nodes can enter into the mode of anomalies automatically, and notify the part of network of entering into the same mode when there are anomalies. We have designed the node and system, and have done experiments in this article. The results show that the system can work well to collect data effectively, and satisfy the demands of precision agriculture.

Key words: wireless sensor network, precision agriculture, information collection, mode selection