NB-IoT Ultra-low power sensing platform

This thesis details the process of creating a low-power NB-IoT development platform that incorporates sensing abilities. It showcases the development process that starts at first with building a basic prototype and later leads to the actual product. The thesis includes appropriate background to better understand the design choices and terminology used when explaining the development process. It explores also the current state of the NB-IoT market to understand better this recently developed protocol and its potential. After that it shifts the focus to exploring the already existing development platforms that are similar to the one covered by this thesis. Following this it starts to delve deeper into describing the actual design process that starts first by building a prototype. The documented prototyping process begins by going into details about the recently developed EVLST87M01 evaluation board used for trying out the features of ST87M01 NB-IoT + GNSS module. After that it shows how another development board was introduced, the X-NUCLEO-U575ZI-Q. The introduction of this board enabled interfacing testing out how the STM32U575 MCU can be used together with the ST87M01 module for the NB-IoT application development. Continuing with building the prototype, the X-NUCLEO-IKS4A1 board with three different sensors was introduced. This enabled seeing how the temperature and humidity, barometer, and accelerometer sensors can be used. Finally, X-NUCLEO-PGEEZ1 was added to evaluate the benefits of EEPROM memory. After successful prototype was built and after evaluation of all of the potential components, the thesis presents the hardware development process for the new development board. It showcases how the development process kicked off with work on the schematics. It presents how abundance of documentation and availability of schematics from previous projects can help in cutting down the development time and bugs. The next step in hardware development, which was PCB design, was outsourced and not a focus of this project, therefore it ended up not being covered by the thesis. Once the first PCBs were available, the thesis shows the process of board bring-up and testing. After testing, it gives details on how the firmware development started, from the BSP to the application level firmware examples. These examples were created in order to better present the capabilities of the newly developed platform. One special example was developed as well to support the usage of the board with STMicroelectronics's data logging infrastructure that is used for easily collecting sensors data and saving it on the PC. Last but not least, the thesis lays out the results obtained when evaluating the performance characteristics of the new platform to get a sense of how the newly created product compares to the existing ones.