This diploma thesis describes with simple bus 1-Wire technology, which is suitable for transfer of data measured by sensors. It describes the standard of bus and 1-Wire and iButton functional elements. This theoretical knowledge was applied during the construction of practical part. There has been a meteorological observatory constructed, which has been described in the next part of the diploma thesis. The last part of dissertation describes online distribution of measured values on internet.

Dagens dataloggare har många funktioner vilket avspeglas i programvaran som används för att kommunicera med dem. De har fler funktioner än vad enskilda företag och privatpersoner behöver vilket gör programvaran onödigt komplicerad. Genom att minska antalet inställningsmöjligheter kan programvaran göras mindre, snabbare och lättare att lära sig. Arbetet utfördes hos Inventech Europe AB som tillhandahöll dataloggare för temperatur- och fuktighetsmätning. De ville undersöka möjligheterna att utveckla ett program som personer med begränsad datorvana snabbt kunde lära sig att använda. Därför var syftet med detta arbete att utreda hur ett sådant program kunde se ut. Arbetets fokus låg på designprocessen. Genom olika UML-diagram visualiserades de olika momenten i processen. Då projektet var relativt litet valdes en utvecklingsprocess som följer vattenfallsmodellen där de olika stegen (specifikation, design, implementation, test) utförs i följd. Det förutsätter att ett steg är färdigt innan nästa steg påbörjas. Modellen fungerar bäst när projektet är mindre och väldefinierat. Tyvärr ändrades företagets krav på hur programmet skulle fungera flera gånger under arbetets gång. Därmed borde en mer flexibel utvecklingsprocess ha valts för att ge utrymme för förändringar som kunde uppkomma under projektets gång. Slutresultatet blev en funktionsprototyp som var lätt att använda och inte hade fler inställningsmöjligheter än nödvändigt. Funktionsprototyp kan användas som bas för att lägga till egen skräddarsydd funktionalitet. För att visa detta inkluderades ytterligare två funktioner. En av funktionerna var möjligheten att kunna spara insamlad data till en extern databas som sedan kunde användas som källa till andra program vilka exempelvis skulle kunna visualisera data med hjälp av olika grafer. För att lätt kunna identifiera olika inkopplade dataloggare inkluderades även möjligheten att namnge de olika enheterna. / Modern data loggers have many settings which is reflected in the application used to communicate with them. They have more settings than individual companies and people need which makes the application unnecessarily complicated. By reducing the number of settings, the application can be made smaller, faster and easier to learn. This bachelor thesis was done at Inventech Europe AB, who provided data loggers for temperature and moisture measurements. They wanted to explore opportunities to develop a program that people with limited computer experience could quickly learn to use. Therefore, the aim of this work is to investigate what such a program would look like. The thesis focus is on the design process. The different steps were visualized through various UML diagrams. Since the project was relatively small, a development process following the waterfall model was chosen. Following the model means completing each step (requirements specification, design, implementation, testing, etc.) in succession. It assumes that one step is completed before the next step is started. The model works best when the project is small and well defined. Unfortunately, the specification given by the company changed multiple times during development. With that in mind, a more flexible development process should have been chosen to allow for changes that may occur during the development. The end result was a program prototype that was easy to use and didn’t have more settings than necessary. The prototype can be used as a base for adding custom functionality. To show this, two additional functions was included. One of the features was the ability to save the collected data to an external database which later could be used as a data source for other application that could visualize the data using different graphs. In order to easily identify different connected data loggers, a second setting was included, enabling naming of the various loggers.

Computer security is a growing field in the IT industry. One of the important aspects of the computer security is authentication. Using passwords (something you know) is one of the most common ways of authentications. But passwords have proven to provide weak level of security as they can be easily compromised. Some other ways of authenticating a user are using physical tokens, (something you possess) and biometrics, (something you are). Using any one of these techniques to secure a system always has its own set of threats. One way to make sure a system is secure is to use multiple factors to authenticate. One of the ways to use multiple factors is to use all the three factors of authentication, something you possess, something you are and something you know. This thesis discusses about different ways of authentication and implements a system using three factor authentication. It takes many security aspects of the system into consideration while implementing it, to make it secure.

This thesis deals with the design and implementation of car computer with multi-user mode and data recording. The measurement is performed by using a direct connection to the sensors and fuel injector of engine. The measured signals are processed and evaluated by Atmel Atmega128A microcontroller. Measured and recorded data are displayed on the graphical LCD.