Undersökning och framtagning av hårdvara för ONE Demand

Sammanfattning: This thesis was done in collaboration with, and on behalf of, One Nordic AB. The purpose was to examine the system One Demand, a system used for sampling measurement data, to begin the development of a new version of the system. The new system is comprised of two parts, a central unit and a graphical user interface. The first step was to find a single board computer, on which the computer program is to be developed, to replace the old central unit. The result was a Raspberry Pi 3 model B which through its digital inputs is able to read pulses from energy meters. Depending on what energy meter is being used and its settings, each pulse is equal to a certain amount of energy in kWh. The GUI, which is written in Python, can count these pulses, allowing a user to set what each pulse amounts to for each meter. Sampling is done, for each meter separately, both by visualizing the energy with a graph and by logging. The graph draws the measured energy in a one-hour period. After an hour has passed the measured energy is first logged on a file before being reset to zero. The graph itself is visualized on a period of two hours and a screenshot is taken before the graphing begins for the next two-hour period. Finally, a technical specification was written. This document specifies the technical data of the central unit and contains user manuals for the central unit and the GUI.