The main target of this thesis is to design and realize a prototype of a high capacity battery charger. The charger has been designed as a switching power supply based on a Flyback convertor with two transistors. As switching transistors the integrated circuit IR2110 has been selected. The convertor is controlled by a microcontroller board based on ATMega328 called Arduino Uno; some parts of the Arduino Uno Starter Kit are also used as LCD display, relay and button. In addition, an auxiliary source has been made; this one powers the integration circuit IR2110 and Arduino Uno board. Furthermore, this work introduces us to the processes of charging lithium batteries, types of lithium batteries and methods of charging the lithium iron phosphate (LiFePO4) battery.

The project was performed in collaboration with the company Prevas AB. The aim of the project was to implement a GPS tracking device, or a GPS tracker, that has a hardware setup retrieving the GPS position of an object and then sends the position through a mobile communication module to a smartphone. A software application running on a smartphone simulator was developed to visualize the position with a Google map widget. The hardware unit consists of a GPS/GSM/GPRS module, a microcontroller, and a smartphone simulator that runs the software application made for iOS, Android and Linux operating systems using Flutter - an UI multi-platform software development kit. Implementation of the setup started with a Telit GM862 GSM/GPRS/3G-GPS module (together with a SmartGM862 development board), an Arduino UNO microcontroller board and a logical level converter. This first setup was not successful because a problem with the serial communication between the Telit GSM-GPS module and the Arduino could not be solved.  The second setup was implemented in which an Arduino GSM/GPRS/GPS shield was used with the Arduino board. The serial communication between the shield and the Arduino was functioning properly and a GPS position could be retrieved. The GPS position is published (sent) using a lightweight messaging protocol - MQTT (messaging queuing telemetry transport) through GPRS functions to the smartphone of the destination user.  To visualize the GPS position in a Google map, an Object Tracker app was implemented on the smartphone simulator app (an iPhone in this project) that subscribes and retrieves the GPS position, and then displays it on the map with a red marker indicating the position.  The GPS tracker with the second setup and the app has been tested and proved to work properly. It has, however, much room for improvement and further development, e.g., making the app more user-friendly, and designing and making a PCB so all the components are mounted on one board. It has been noticed in an initiated test that the GPS antenna placement could affect  positioning accuracy. This, thus, needs to be considered for high accuracy.

Solar energy is a clean energy source which has a minimal impact on the environment than other forms of energy. Solar energy is now widely used in a variety of applications. Although solar energy is widely used, the efficiency of converting solar energy into electricity is insufficient since most solar panels are installed at a fixed angle and the fixed solar panels do not aim directly towards the sun due to the earth’s constant motion. Solar panels are very expensive for families or businesses that consume more energy than usual, as they require several solar panels to generate enough power. The main objective of this project is to build a working model so that to increase the efficiency of power output taken from solar panel by continuously tracking the sun’s rays through out the day and aligns the solar panel orthogonal to the sun. To develop a model that benefits people by producing more solar energy with fewer solar panels. In order to overcome this problem we come up with a solution through Arduino Uno system which consists of four LDR sensors which are responsible for the detection of the light intensity of the sun’s rays. Two micro servo motors are used for movement of the solar panel in azimuth and elevation direction since it is a dual axis tracking system. A solar panel is the core part we use in this model for the conversion of solar energy into electrical energy. The LCD displays shows the power output of the solar panel. The proposed system is a dual axis tracking system that actively tracks solar radiation and adjusts the panel so that the sun’s rays are perpendicular to it, maximizing the solar panel’s power output. The LCD display shows the power output of the solar panel. By this project, we can say that dual axis tracking system we built can track the sun’s rays and increases the power output of solar panel. The manual effort for changing the solar panel according to the sun position can be avoided.

In modern world sensors play important role where they help to acquire information about the procecess, such as temperature, velocity,distance, etc. Based on this information acquired from the sensorsdecisions can be made, for example to increase heating in the buildingor accelerate the car.In many cases, a single sensor type cannot provide enough information for complex decision making, for example, when the physicalproperties of the process are outside of the measurement range of thesensor. As a result, in order to achieve desired performance levels, acombination of sensors should be used in an integrated manner.Sensor generated data need to be processed into information throughthe use of appropriate decision making models in order to improveoverall performance. Here we compare two sensors which are shortrange and long-range sensor. We use a short-range and long-rangesensor, and calculates the distance from both sensors to the same object by using Arduino UNO microcontroller. The sensors that we usein our work have overlapping or common interval in their measurementranges. Therefore we investigated how we can make a decision aboutthe distance to an object when the acquired data from both sensors isin that common range.

We use autonomous line-following robots in various industrial environments, surveillance applications, and construction and mining industries for object transportation tasks where rail, conveyer, and gantry solutions are unavailable. They help us reduce the work process and improve efficiency. In this report, we will illustrate how a 2WD robot can move on a predefined path and detect obstacles along the way. In this project, we have used a proximity sensor to detect the obstacle in the path and turn the robot from the obstacle. Also, we used an IR sensor so that robot could follow along the predefined path. The used in the project sensors were connected to Arduino UNO, which was programmed to control the robot's movements and decisions. By employing these two techniques, we can efficiently use such robots in various scenarios. For example, in the current Covid scenario, physical contact has become minimal, so if we use this line-following robot to deliver medicines to the patient, the physical contact between people can be reduced. The obstacle avoidance robot technique can be used in cars to improve safety. If an obstacle is detected in the path of the car and the driver does not apply the brakes, this type of technique can be used to bring the car to a stop by applying breaks. Using the proposed robotic techniques we can save time and work efficiently with minimal physical touch. Overall, the project achieved its primary goal of moving the robot on a predefined path and detecting obstacles on the path

Tennis is a popular sport and in summer it’s often played outside. When an outdoors tennis court has been used it needs to be brushed. First the whole court is brushed witha large brush and then the white lines with a smaller brush. The aim of this thesis was to design and build a working prototype of a robot who can do all of this by itself i.e sweep the court and then the white lines. The budget for components to the prototype was limited to 1 000 SEK. Tools and other resources such as 3D-printers, soldering equipment and laser cutters was provided by KTH for free. First information and inspiration about self-driving cars and driving patterns was collected and some important sources were old bachelor’s thesis. Then, needed components and dimensions could be determined. In this project the main components were an Arduino Uno, two DC motors, an L298H-bridge, an ultra sonic distance sensor, an on/off switch, AAA batteries and a 9 V battery. The conclusions that could been drawn was that the robot can work good enough to sweep a court with only a preprogrammed path. However, to sweep the white lines, sensors would be necessary. It could also be concluded that a robot could sweep the court at the same speed as two people could do it. / Tennis är en populär sport och på sommaren spelas den ofta utomhus. När en utomhustennisbana har använts måste den borstas. Först borstas hela banan med en stor borste och sedan de vita linjerna med en mindre borste. Syftet med denna uppsats var att designa och bygga en fungerande prototyp av en robot som kan göra allt detta av sig själv dvs. sopa tennisbanan och sedan de vita linjerna. Budgeten för komponenter till prototypen var begränsad till 1000 SEK. Verktyg och andra resurser så som 3D-skrivare, lödutrustning och laserskärare tillhandahölls av KTH gratis. Det första som gjordes var att samla information och inspiration om självkörande bilar och olika körmönster och några viktiga källor var gamla kandidatexamensuppsatser. Sedan kunde nödvändiga komponenter och dimensioner bestämmas. I detta projekt var huvudkomponenterna en Arduino Uno, två DC-motorer, en L298 H-brygga, en ultraljudssensor, en på/av-omkopplare, AAA-batterier och ett 9 V batteri. Slutsatserna som kunde dras var att roboten kan fungera tillräckligt bra för att borsta en tennisbana med endast en förprogrammerad bana. För att sopa de vita linjerna skulle sensorer dock vara nödvändiga. En annan slutsats var att en robot kan sopa banan på samma tid som det krävs för två personer att sopa varsin halva.

Context: Solar panels are exposed to different weather conditions and get damaged. Sand storms and hail storms could cause serious damage. However, they need to be used for human survival in almost every harsh condition possible. Objectives: Our goal is to design and create a working prototype of an automated solar panel shield. The meteorological conditions around the solar panels should be monitored, including wind speed, air quality, rain, and humidity. The shield automatically protects the solar panel based on the sensor data. The solar shield should even protect panels from harm from small animals. Methods: A microcontroller Arduino Uno is used. Various sensors are used to monitor multiple weather conditions, including an ultrasonic sensor, a rain sensor, a smoke sensor, and a custom-built anemometer. Based on daylight status, the stepper motor is activated to roll up the protective cover over the solar panel. Results: The output from all the sensors and actuators is verified. The values of the sensors are updated in the web application, the user can use that. The web application is used to monitor the weather conditions around solar panels. Conclusions: An working model of the shield is made, in addition, a cleaning system is made. A bird deterring system is also included. All the additional sensors for monitoring can be used for performance automation.

What is the purpose of medication? It’s job is to cure a disease.But taking medicine at the perfect time will definitely help anyonecure diseases immediately. There are so many situations when missingmedicine timing might happen unintentionally or even expected. Forexample, there are diabetic people who miss their shot of dose atperfect timing. Another example is the people with memory issuesdue to age or disease.There are many situations where missing medicine might causeproblems. Mainly in crisis situation like in hospital we need a re-minder that helps people take the preferred medicine at specified time.So that will be the problem statement of this thesis.The main objective of the thesis is to notify patient take correctmedicine with the help of easy equipment. When elders have a prob-lem we admit them in hospitals but due to COVID epidemic situa-tions hospitals are understaffed. Because of that the patients in hos-pitals may not be treated well. The personal has a busy schedule withCOVID situations so they can’t care must about each and every singledetails. This might causes major problems while giving minute dosesto patient where a 1mg medication change can lead to severe problemsfor a patients health condition. By providing a proper check up withpatient we can solve those problems more effectively.

Aim of this thesis is a verification of possibility to measure displacement in small range using sensor based on the principle of strain gauge. For testing purspose, an evaluating unit was designed, made and assembled. This unit contains analog/digital converter, LCD and it has an abbility to move measuring plane using stepper motor. Next part of this thesis is about testing new prototype of strain gauge sensor, including evaluation of results of measuring. The performed measurements were measuring linearity, time stability and repeatability. Based on the results of the measurements, the possibility of using this type of length measuring device was confirmed for further development.

This degree project investigates the possibility to develop and re-design an IoT solution called NOT!FY, offered by the company Omnitor. NOT!FY is used by users who are hard of hearing or deaf as a complement to an accessibility communication application. It functions by registering incoming calls and activating a relay connected to, for example, a light source, notifying the user. The current problems that Omnitor experiences with NOT!FY is its price, production difficulties, size and design. The project will take on these problems by investigating the market of programmable devices and, through comparative analysis, choosing a platform to transfer and improve upon the current NOT!FY functionalities. The devices were decided together with Omnitor and a grant calculation was drafted to evaluate which units yielded the best profit. With the help of the grant calculation, Raspberry Pi Zero W and ESP8266 were the chosen devices. A basic evaluation was performed to verify that the implemented functions of ESP8266 and Raspberry Pi Zero W functioned as intended. An in-depth evaluation and functional verification were performed on the finalized prototype. It confirmed the prototype’s functionality and the possibility to replace the current product in use by Omnitor. / Detta projekt undersöker möjligheten att utveckla och designa om en IoT-lösning kallad NOT!FY, som erbjuds av företaget Omnitor AB. NOT!FY används av döva eller hörselskadade användare som ett komplement till en tillgänglighetsanpassad kommunikationsapplikation. Den fungerar genom att registrera inkommande samtal och aktivera ett relä som är anslutet till exempel en ljuskälla för att meddela användaren. De nuvarande problemen som Omnitor upplever med NOT!FY är dess pris, produktionssvårigheter, storlek och design. Projektet kommer att ta sig an dessa problem genom att undersöka marknaden för programmerbara enheter och genom en jämförande analys välja en plattform att överföra och förbättra funktionerna från den nuvarande produkten. Enheterna bestämdes tillsammans med Omnitor och en bidragskalkyl är framtagen för att utvärdera vilka enheter som gav bäst vinst. Med hjälp av bidragskalkylen var Raspberry Pi Zero W och ESP8266 de valda enheterna. En grundläggande utvärdering utfördes för att verifiera att de implementerade funktionerna i ESP8266 och Raspberry Pi Zero W fungerade som avsett. En mer ingående utvärdering och funktionell verifiering utfördes på den färdiga prototypen. Detta bekräftade prototypens funktionalitet och möjligheten att ersätta den nuvarande produkten som används av Omnitor.