978-1-7281-2868-9/19/$31.00 ©2019 IEEE An IoT LDR Bulb Application with Android Things Operating System for Smart Cities Sadik Arslan R&D Department Kent Kart Ege Elektronik A.Ş. İzmir, Turkey sadik.arslan@kentkart.com.tr Orhan Dagdeviren International Computer Institute Ege University İzmir, Turkey orhan.dagdeviren@ege.edu.tr Geylani Kardas International Computer Institute Ege University İzmir, Turkey geylani.kardas@ege.edu.tr Abstract—Nowadays, Internet of Things (IoT) is a highly active research area with wide range of industrial applications such as smart city services. These applications generally aim to meet the growing demands of society in terms of power, water, gas, and lighting services. Although there are studies related to this area, technological developments in terms of both hardware and software lead to better solutions. In this study, an IoT application which is a key feature for a smart city service has been developed for street lighting. The developed application works with a light dependent resistor (LDR) and it controls a bulb according to the ambient light intensity. The control information is kept and analyzed in a cloud environment. Raspberry Pi development environment and Android Things operating system are used for realization of the system. Light bulb control and LDR hardware circuits have been developed within the scope of this study. With this study, a platform has been developed which can be realized at an affordable price to add additional sensors such as air pollution and humidity. Additionally, the easy development possibilities of the Android Things operating system have been examined. Keywords—Internet of Things, Android Things, Raspberry Pi, Smart City, Smart Lightning I. INTRODUCTION The Internet of Things (IoT), frequently heard today, is a worldwide network of uniquely addressable objects (nodes) that are generally embedded in the environment [1]. These systems are generally designed for special purposes to perform predefined tasks. An IoT node is mainly composed of a processor, a memory, communication units, clock, secondary storage units and power supply as given in Fig. 1. The nodes residing in IoT network communicate with each other through specific protocols. IoT concept can simply be explained as a system of devices that communicate with each other through a variety of Internet communication protocols, and create an intelligent network by sharing information [2]. Fig. 1. Simplified IoT node block diagram. With smart technologies, it is possible to implement different applications to solve the problems of the society in the cities to managing the resources better. In the vision of “smart city”, IoT has a very important and strategic position that can be described as a prerequisite. Applications that will improve the city life are realized by analyzing the data coming from the connections and sensors provided by IoT. These applications provide wide range of services such as power, water, gas and lighting. Although there are efficient applications in this area, technological advancements in hardware and software bring new opportunities to enhance the capabilities of current services. In this paper, we give the design and development of an IoT based smart street lighting application. Our proposed system works with a light dependent resistor (LDR) to control the bulb according to ambient light intensity. We deploy a cloud infrastructure to store and analyze the control information generated by the system. Light bulb control and LDR hardware circuits are designed and developed. We use Raspberry Pi and its development environment with Android Things operating system. This operating system is implemented by Google to use the existing widely used Android development tools, application programming interfaces (APIs) and resources [3]. The rest of the paper is organized as follows. In Section II of the paper, related work is given. In Section III, an overview of IoT concept is discussed. In Section IV, Android Things operating system is examined. In Section V, the designed system is described in detail as hardware, software and cloud platforms. In the last section, conclusions are drawn. II. RELATED WORK Smart cities provide a wide range of applications to society through IoT and many technologies. Smart parking, structural health monitoring, traffic congestion management, waste management, fire detection, air pollution detection and smart lighting are significant examples of these applications. With the help of smart lighting, energy efficiency as well as automated control will be provided. IoT based smart lighting is an attractive research area [4 - 7]. The study given in [4] is a solar supplied lighting system for smart city control cards. In [5], Raspberry Pi development environment is used for control of the IoT system hardware to provide smart lighting. A supply system design for smart cities is given in [6]. Energy efficiency is very important in IoT applications [7] especially for smart home related services [8 - 10]. In study [8], IoT system can be controlled by an Android smart phone application. Green house environment is provided in [9]. In [10], sensors nodes are used for IoT system development. There also exist IoT studies using LDRs in many fields such as farming [11], environmental monitoring [12], solar tracking [13], office [14] and renewable energy [15]. In all of these studies, operating systems are used as Linux and its derivatives and