INTEGRATION OF HOUSEHOLD APPLIANCES TO THE EXISTING INTERNET INFRASTRUCTURE

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1 10th International DAAAM Baltic Conference "INDUSTRIAL ENGINEERING" May 2015, Tallinn, Estonia INTEGRATION OF HOUSEHOLD APPLIANCES TO THE EXISTING INTERNET INFRASTRUCTURE Airola, A.; Jousimaa, O.; Niemi, K.; Vuokko, S.; Kiviluoma, P. & Kuosmanen, P. Abstract: The Internet of Things (IoT) is an interconnection between uniquely identifiable computer systems and existing Internet infrastructure. The field is quickly growing while large companies are starting to take interest in it. To study possibilities and challenges of Internet connected devices, an ordinary coffee maker was modified to receive commands and send status over the Internet as a first experiment. A smartphone application was built as a controlling user interface. Adding Internet connectivity was forthright to accomplish, but delay of message delivery did real time control unfeasible. This study approached the problem by considering how to add value to basic devices with relatively low-priced components. The ultimate outcome would be a future household where appliances can communicate with each other and the user. Key words: Internet of Things, WiFi, Home Automation 1 INTRODUCTION The Internet connected computer systems can currently be small embedded microcontrollers, which can be installed virtually to any possible object. These devices can vary in size from a large industrial paper machine to tiny heart monitoring implant or biochip. Their function can be either passive or active depending on whether they have only sensors to measure current function of the machine or also actuators so that the device can be remotely controlled. It is common between many of these applications to utilize an IP address (IPv4 or IPv6) as a handle [2]. Thus each machine can be monitored or controlled individually. In recent years, IoT has been making a significant breakthrough in every industrial field. In addition, home automation utilizing IoT is increasingly adapting to our household appliances. It is a concept of utilizing cloud services to improve user experience of everyday devices. Because the field is quite novel, there are a lot of elementary research to be done. [3] Smart household devices have existed for many years [4] but still none of them has become commercially successful. Many of them are too futuristic or highly priced to fit every household. Rapid development of technology and lack of multi-vendorplatform have limited lifecycle of intelligent household devices [3] [5] [6]. In this research paper, new ways to incorporate Internet to existing, everyday household appliances will be investigated. As a part of the project, an expandable platform and a few demonstration applications were built. The main ideology was integration: same user interface can be used to control multiple different household devices [7]. Second key-concept was to utilize existing infrastructure such as WiFi connection and smartphones. The first goal was to build a coffee maker, which is remotely controllable via smartphone application. The main idea was that the coffee maker is able to dose the correct amount of water and coffee ground [1]

2 based on the user input. The coffee maker is controlled by a WiFi connected microcontroller, which communicates with a cloud server. The server is a proxy between the coffee maker and the smartphone. The secondary goal was to add more appliances to be controlled with the same smartphone application. LED lighting was decided to be incorporated to the platform. This way a smart wake-up feature incorporating wake-up alarm, coffee maker and lighting could be implemented: When the alarm shuts off, lights and the coffee maker turn on. Data security of IoT is excluded from this research. The basic working principle of the whole system is shown in Figure 1. Fig. 1. Basic working principle of the system. 2 METHODS 2.1 Coffee maker Safety is one of the highest priorities. To ensure safety, the supply voltage circuitry was decided to be kept as simple as possible. This led to use on-off relays as controlling the AC power to the coffee maker. Water supply is strictly limited to separate water tank to avoid water damages. Arduino Mega microcontroller platform was chosen for its easy connectivity and prototyping features. It also offers great expandability to integrate all desired features but lacks performance to have modern stand-alone user interface. If the device would be mass produced, a custom solution would be justified. ESP8266 WiFi module [8] was used to enable internet connectivity. The third keycomponent was relay board which was used for on-off switching. Devices connected to the relay board were a dosing pump and a coffee maker. Coffee-grinddispenser brought a significant factor of uncertainty. That was caused by its mechanical properties. Required operating torque was discovered to be variable and unknown which led us to select a stepper motor with high torque. Coffee-dispenser was driven with stepper motor attached directly to the rotor, instead of its original crank mechanism. To control the stepper motor, a stepper shield was used. The inlet water hose from the external water tank was attached to the same water line which moves water from coffee maker s own water tank to the coffee filter during brewing. The target was that all the components would be hidden into the base to achieve more finished appearance. The coffeegrind-dispenser was the only visible component due to its location on top of the coffee maker. To fit the dispenser and the stepper motor sturdy to the coffee maker s frame a separate support was manufactured by 3D printing. The basic schematic of the coffee maker unit is shown in Figure LED lighting In addition to coffee maker, a separate control box was developed for LED lighting. Similarly, Arduino Nano and ESP8266 were chosen for control and communication. The control box was designed to support PWM output. Thus the brightness of lights could be adjusted in the user interface. In theory, any other low-voltage and lowpower device could also be connected to this expansion box.

3 Nr. Component 1 Smart phone 2 Cloud 3 Control box for LEDs (inc. Arduino Nano and WiFi module) 4 LED lights 5 WiFi module 6 Arduino Mega 7 Stepper motor 8 Coffee grounds dispenser 9 Water pump 10 Water tank 11 Coffee maker Fig. 2. Basic schematic of the system. 2.3 Programming microcontrollers The Arduinos were programmed using C++ based Arduino programming language [9]. For each subsystem, a separate function was created to ease the task of coding the control sequences in the main loop. First the codes were implemented to control coffee maker and LED lights through the local serial monitor via PC. Later, the WiFi module was incorporated to the code to read the commands directly from the cloud-based server. 2.4 Android application Android application was designed with Android Studio [10] to give an easy and intuitive way for the user to control connected devices. It allowed separate control of the coffee machine and the lamp or simultaneous control of both of the devices. The separate control allowed the user to choose the amount of coffee cups and the time when it starts brewing. Lamp control enabled the user to choose brightness of the lamp on scale from zero to hundred, zero meaning it was switched off. The application also had a wake-up mode which allowed the user to choose a time to wake up. The mode set a wake-up alarm, brewed selected amount of coffee and turned the lights on at that time. 2.5 Cloud server A public Internet facing server acted as a mailbox between the devices. This solved the problem on how different devices could find each other regardless of possible firewalls, NATs or other issues. The server itself didn't have any control logic, it only took data in and presented it in suitable format to user. Having a publicly available connection allowed to have devices controlled from anywhere, it led to a unpredictable lag between sending and receiving commands. Since security is outside the scope of this paper, even basic authentication or encryption in commands wasn t implemented. 3 RESULTS 3.1 Wireless communication The wireless communication between the microcontrollers and the server worked well most of the time. The microcontrollers were pre-programmed to connect to the server every minute and check whether there are any new commands. However, in crowded networks the WiFi modules had some difficulties in connectivity and it took

4 up to ten minutes to get the command transmitted to the device.

5 Fig. 3. Pumping performance data of dosing pump. Wireless connectivity between server and device had also significant latency and jitter in response times. In practice this means that any real-time control over TCP/IP is not feasible, and local microcontroller had to control every timesensitive task such as pumping and dosing. 3.2 Coffee dispensing The automated water dispensing system proved to be reasonable accurate. The pumping data can be seen from Figure 3. As it is presented in the graph, the dispersion of the flow rate is quite low so the closed-loop control wasn t required in the system. On the other hand, the coffee ground dispenser had some issues with moisture condensing inside the dispenser and contaminating the unused coffee grounds. Also the spinning rotor in the dispenser got occasionally jammed because of small coffee ground particles getting wedged between surfaces. However, by grinding wider clearance to the rotor, the problem was solved. The software of the coffee maker was rather simple, linear program. The program polled for new instructions from server roughly at one minute interval, and acted on any commands received. Figure 4 shows the program flowchart of the coffee maker. 3.3 Light dimming The light dimming using PWM turned out to be straight forward to implement. The device controller had three distinct modes: WiFi controlled, Manual controlled and off. The modes selected the source of data: on WiFi mode, data was polled from the server. On Manual mode, user could press the buttons on controller to adjust the duty cycle of PWM outputs. Off mode was for the convenience, it set all the outputs to 0 %. Device also had a watchdog timer to guard against software lockups. In each cycle of the program, a watchdog timer was reset. If the watchdog timer was not reset in eight seconds, the software would be reset and started from initializing the hardware peripherals. Figure 5 shows the program flowchart of LED lights.

6 With the status page, the user could also easily check the current command send to the coffee maker and LED control box. Fig. 5. Software structure of LED lights. Fig. 4. Software structure of coffee maker. While using the coffee maker and the LED lights in the same network, there seemed to be some interference between the devices and the other device occasionally refused to work. By further software tuning, this issue could be achievable to overcome. 3.4 User interface The Android application (Figure 6) turned out to be simple and easy to use. The application had an individual button for each function (coffee, lights, wake-up) and easy sliders to set the right time and amount of cups. Fig. 6. User interface. 4 CONCLUSIONS Internet connection could be used to relay high-level commands, such as Brew 6 cups of coffee at However, unpredictable lag in communication prevented real time control of the system,

7 so local device had to control time-critical tasks such as dosing water. Intelligence in device is important to verify the safety limits of commands, for example to avoid dispensing water amount exceeding water tank capacity and causing water damage to floor structures. If remote operator does not have a line of sight to device being controlled, fault conditions can lead to catastrophic failures. Therefore Internet connected devices should have even more robust safety electronics, such as sensors, than most current household devices. User interface design is extremely important to maintain easy user experience Devices should have a way of presenting status for example to remind user for filter changing. Overall, the project showed that IoT has potential to adapt to everyday household devices. Additional component cost is not the greatest challenge decelerating generalization of IoT but lack of deviceunifying software and hardware platform. By further developing and standardisation, safe and useful concepts could be created. 5 REFERENCES [1] Katasonov, A. & Kaykova, O. & Khriyenko, O. & Nikitin, S & Terziyan, V. Smart Semantic Middleware for the Internet of Things, [Referenced ] [2] 3Com Corporation. Understanding IP Addressing: Everything You Ever Wanted To Know, [Referenced ] [3] Adiono, T. Challenges and Opportunities in Designing Internet of Things, [Referenced ] [4] Withanage, C. & Ashok, R. & Yuen, C. & Otto, K. A Comparison of the Popular Home Automation Technologies, [Referenced ] [5] Wang, W. & Lee, K & Murray, D. Building a Generic Architecture for the Internet of Things, [Referenced ] [6] Nasrin, S. Novel Protocol Enables DIY Home Automation, [Referenced ] [7] Hodges, S. & Taylor, S. & Villar, N. & Scott, J. Prototyping Connected Devices for the Internet of Things, [Referenced ] [8] Espressif Systems. ESPRESSIF SMART CONNECTIVITY PLATFORM: ESP8266, [Referenced ] [9] Arduino Reference page. nce/homepage [Referenced ] [10] Android Studio home page. k/index.html [Referenced ] CORRESPONDING ADDRESS Panu Kiviluoma, D.Sc. (Tech.), Senior University Lecturer Aalto University School of Engineering Department of Engineering Design and Production P.O.Box 14100, Aalto, Finland Phone: panu.kiviluoma@aalto.fi ADDITIONAL DATA ABOUT AUTHORS Airola, Antti, B.Sc. (Tech.) antti.airola@aalto.fi Jousimaa, Otso otso.jousimaa@aalto.fi Niemi, Kalle kalle.niemi@aalto.fi Vuokko, Sami, B.Sc. (Tech.) sami.vuokko@aalto.fi Kuosmanen, Petri, D.Sc. (Tech.), Professor Phone: petri.kuosmanen@aalto.fi