# GreenLab, an IoT-Based Small-Scale Smart Greenhouse
## 1 Introduction  
With the development of the Internet of Things (IoT), new emerging technologies become more accessible to developers providing, among others, solutions for smart and sustainable agriculture and bringing alternatives to global problems such as the food crisis. With the help of IoT, smart technologies and data analysis can be used to face challenges like climate change, poor soil, and lack of labor [1]. Water, energy, and food are resources that are inevitably connected. Climate often plays a decisive role in food production as well. A major impact on one resource implies major imbalances in the other two. Taking into account the fact that, for the normal development of the human body, an almost daily intake of fresh fruits and vegetables is necessary and taking into account the irregularity or blockage of imports, the problem of the lack of fresh fruits/vegetables, the problem of import substitution remains a pressing problem in many countries. One solution, which is already successfully applied, is the creation of greenhouses and mini/micro greenhouses, which allow the cultivation of vegetables and fruits and thus eliminate expensive imports. Smart greenhouses allow farmers to grow desired crops with minimal human interference. Climatic conditions such as temperature, air humidity, brightness, and soil moisture are continuously monitored inside a mini-house with the help of a sensor system. Variations in indoor environment conditions automatically lead to their correction using heating/cooling, irrigation/drying, and lighting systems to maintain optimal conditions for plant growth. The development of interconnected intelligent systems can generate opportunities to effectively address the challenges of food shortages and fluctuating supply chains. Current research shows how IoT technologies are explored and used in smart greenhouses [1]. The most notable research trends consist of network architectures [2; 3], advanced controlling techniques [4; 5], energy efficiency [6], interoperability [7], advancedtechniques for data acquisition [8] and security challenges [9]. In [8], the most notable technologies with the greatest potential were identified to include cloud, fog and edge computing, embedded systems, communications protocols like LoRa, ZigBee, GPRS, and different interfaces like API, H2M, and M2M. All of these are parts of modern IoT architecture. Besides the advantages, the IoT-based solutions are still facing several challenges regarding the need of to standardize IoT infrastructure in the agricultural sector, technological challenges regarding connectivity in developing countries, and the need to align corporate farming practices with global patterns [8]. This paper presents an experimental Internet of Things-based small-scale greenhouse prototype as a proof of concept for the benefits of merging smart sensing, connectivity, IoT, and mobile-based applications, for growing cultures. Our proposed solution includes a photovoltaic panel and a buffer battery for reducing energy consumption costs, while also assuring functionality during night and cloudy weather, and a mobile application for easy data visualization and monitoring of the greenhouse. This paper is structured in five sections. The first section, called the Introduction, describes the field of research and places our solution in the broad context of IoT-based greenhouses, continuing with the second section, Related Work, which describes the state of the art in this field. The proposed solution is described in the third section, called the GreenLab Project. Data readings are presented and discussed in the Results section. The paper ends by summarizing the main conclusions in a dedicated section.