It has been a really busy month for the smart farm team. While involved with a lot of activities in school, the team has been hard at work completing the project. The team has gotten further along in the design process. We have been focusing most of our time on the design of the wireless sensor network and the cloud computing aspect of the smart farm. We are implementing a wireless sensor network for the monitoring of the plant and soil factors.
Wireless Sensor Networks consist of three types of nodes. They are: the coordinator/gateway which organizes the network and helps to maintain routing tables; the routers which communicate with coordinator and other routers to reduce the functions of end devices and provide paths for end devices to communicate data to the base station or coordinator; and the end device which interfaces to the physical world. It senses the parameters for which it has been designed and communicates with coordinator through desired routing protocol and forward signal to the base station. Wireless Sensor Networks (WSNs) can be used to monitor different environmental parameters related to agriculture such as temperature, humidity, weather station, leaf wetness and many other parameters. The monitoring of these parameters allows for the efficient management of time and money as well as the maximization of agriculture results.
The sensor node acts as the end device by interfacing to the physical world i.e. it interfaces to the farm sensors to read the farm data like soil temperature, soil moisture and others. The sensor node also acts as a Router due to the powerfully equipped antenna and wireless transmission protocol it uses. The sensor node is based on the Atmega 328P microcontroller and the XBee 2mW Wire Antenna – Series 2 (ZigBee Mesh). For the ZigBee Transceiver, we are using the XBee XB24-Z7WIT-004 module from Digi (XBee 2mW Wire Antenna – Series 2 (ZigBee Mesh). Series 2 improves on the power output and data protocol. Series 2 modules allow one to create complex mesh networks based on the XBee ZB ZigBee mesh firmware. These modules allow a very reliable and simple communication between microcontrollers.
We have carried out some simulations on the sensor node design using the Proteus EDA Software and some other package. Also for our coordinator/gateway, we are using the popular open source hardware, the Arduino. We are currently deciding between two design models. One is based on the Arduino Uno, Arduino GSM/GPRS Shield and some other shields while the other is an unpopular development board, the Gboard (http://imall.iteadstudio.com/im120411004.html). Although we have faced some few challenges, we are looking forward to setting up working sensor network soon on a real farm. It will be fun. As for our Cloud part of the farm system, things seem to be going well as we have already created a design layout.