Integration of Autonomous Wireless Sensor Networks in Academic School Gardens

In this work, the combination of capabilities provided by Wireless Sensor Networks with parameter observation in a school garden is employed in order to provide a comprehensive environment for school garden integration as a complementary educational activity in primary schools. Wireless transceivers with energy harvesting capabilities are employed in order to provide autonomous system operation, combined with an ad-hoc implemented application called MySchoolGardenApp. The system enables direct parameter observation as well as data analysis and processing capabilities, which can be further employed with students in a cloud based platform. Providing remote data access allows the adaptation of content to specific classroom needs. The proposed WSN for monitoring the orchard located in the schoolyard of a primary school has been built with EnOcean’s energy harvesting modules, operating at 868.3 MHz with a data rate of 125 kbps and transmitting between 5-8 dBm of power. These wireless modules have incorporated a temperature sensor and there is the possibility of equipping them with a humidity sensor. Each module communicates only with a central module connected to a PC or laptop via USB, in a star topology. For the assessment of the wireless link quality and the deployment of the modules, especially the central module which needs to receive directly the signals of all the sensor modules, simulation results obtained by an in-house developed 3D Ray Launching deterministic method have been used. Preliminary trials with MySchoolGardenApp have been performed, showing the feasibility of the proposed platform as an educational resource in schools.