Autonomous Smart μGreenhouse: Analysis of Power Consumption Cum-sine IoT NodeMCUs ESP8266

Abstract

This study presents the results of the first stage of the “COMMON Initiative: Climate-Smart Agriculture Demonstration Plot” project at the University of Central Asia – developing an autonomous smart micro-greenhouse with low-cost IoT equipment (two NodeMCU ESP8266 boards, four 3V relays, and sensors DS18B20/DHT11/LDR/YL-69) and analysing its power consumption in relation to the IoT component. The experiment with eight commonly cultivated plant species (dill, garden strawberry, lettuce, stock, basil, parsley, sorrel, and spinach) in two identical μgreenhouses of size 30x 26x 20cm each (testbed located at the elevation of 800m – Bishkek, Kyrgyz Republic) demonstrated that the power consumption is less with IoT equipment because the use of plant grow lights and heaters is minimised. Observational findings indicate that six plants (except basil and garden strawberry) grew faster in a smart μgreenhouse. The control algorithm employs one-input hysteresis with a neutral zone to automatically regulate the light and temperature inside a μgreenhouse. The percentage change for two time series (cum-sine IoT equipment) varies from -0.92% to -5.78% during the experiment. The data on temperature/soil moisture inside and the temperature/humidity/light intensity outside a μgreenhouse are provided to the human expert to support the decision-making process on plants’ watering. In the second stage of this project, a machine learning algorithm will be employed to further minimise power consumption.