Temperaturlogger

Sammanfattning: Temperature has been and still is an important quantity that needs to be measured and logged for different applications from industries to our daily life.  This bachelor thesis aims to design a prototype for a temperature logger that can log temperature from four external thermocouples over the temperature range between -20 and +85 degrees during the time of four months with a set update frequency every 15 minutes. The prototype should programmable and be able to communicate with a PC and transfer measurement data to an SD card for storage. The V-model (a development process model) is used to create documents and confirm them in the later stages of the product development process. In the beginning of the project there was a general search for information about similar products and then a decision making on how the project was going to be conducted.  Following the “V-model” the project several surveys have been done regarding the functionality of different components. From there, decisions have been made from the results of what component is the best for this specific project. The components have then been used to design a full electric system with all the components connected, generating an overview of the whole system. After the system design, a printed board circuit (PCB) was designed using Altium Designer, for which all the previous information gathered in the documents was used, including the components chosen earlier and all the small components decided later based on the component’s datasheets. Due to the limited time of ten weeks for the project as well as the lack of experience in scheduling each step in the product development process, this degree project ended up only with finishing the design of the PCB but not the physical prototype. For the future work, it is suggested to add more external thermocouples in the temperature logger since the more thermocouples the logger has, the more analysis it can make at the same time and thus the more efficient the product can become. Besides, the algorithm for temperature logging can be made adaptive according to how fast the temperature changes. For instance, the logger is less frequently activated for lower temperature change. This can significantly reduce unnecessary workload and data storage to save energy and storage resource.