Design fabrication and development of low cost smart iot based site specific sensor devices for precision agricultural farming

Abstract

This work brings in an eco-friendly, smart integrated miniaturized sensor system to determine the temperature, nitrate nutrient of aqueous solution and soil in a more affordable way to yield quality of farming, small-scale agricultural farming, greenhouse farming, domestic gardening, and hydroponics. Carbon-Graphite hybrid electrode-based planar disposable sensor strip is used for sensing the temperature over a range of 27 °C to 50 °C. The meander geometrical structure is inferred, because of comparing the temperature sensor element to four different structural types, both experimentally and through modelling. The temperature sensing element is fabricated utilizing a prudent, efficacious, and inexpensive microfabrication methodology of screen printing. The temperature coefficient of resistance is determined to be 1% / °C for PET and 0.8%/ °C paper substrate in soil. The temperature sensor strip is integrated with a Wi-Fi SoC assisted nodeMCU processor that is used in IoT platforms. An app is created using MIT app inventor user interface and is launched on an android smart phone. The app gives the suitable temperature range for sowing seed and germination of the plant growth information. A site-specific sensor for sensing soil nitrate nutrient helps precision agriculture farming is also constructed by screen printing of electrodes. The ionic concentration in the soil extract is identified based on the difference in potential between the working and reference electrode and therefore the respective specific ions are thus identified. The CNT_ ZnO solid contact based newlinepotentiometric ion selective electrode produces a mean detection limit of (5.7244±0.11) x 10-6 M. The proposed work details the design, modeling, fabrication, and integration with a smart electronics reader system for soil temperature and nitrate NO3-. The wireless sensors collect data from the soil newline newline newline