This bachelor's thesis is about the designing process of a microcontroller data logger unit, summarizing the expectations towards data acquisiton units, wireless sensor networks and information about the unlicensed use of ISM band radio frequencies.
I review the structure of the system, the chosen electronic components, the design of the circuits, the completed and planned steps of development, testing and future development possibilities.
The first chapter is about the connection between my task and the reviewed theoretical literature about data acquisition systems and wireless sensor networks.
The second chapter deals with the theory of wireless sensor networks and the solutions that are available on the market.
The third chapter summarizes the most substantial facts about the regulation of ISM radio bands.
The fourth chapter introduces the structure of the system, which means specifying the expectations towards the remote unit on the field, and the central unit handled by the user.
In the fifth chapter I review the chosen hardware parts and in the sixth chapter the steps of firmware design related to those. The system contains AVR microcontrollers, to which many peripherals are attached using SPI bus. I wrote in detail about the peripherals which are not trivial to use. Implementation of the communication protocol and providing data reliability through the use of checksums is a task yet to do. Software tasks regarding battery-level check are also examined.
The seventh chapter is about getting the system to work and testing, and the last chapter is the summary of the former chapters and the development possibilities.