Automatic Dosing Unit for Pool Chemistry

The objective of this thesis was to design and construct the dosing unit for pool chemistry with the features of common available equipments, but with lower acquisition costs compared to these equipments. The initial part of this thesis describes the requirements for water quality in the pools and the principles of its sustaining. The next section describes the ESP32 microcontroller, which was selected because of sufficient computation power and memory resources and RF connectivity capability. Furthermore, the pH, ORP probes and temperature sensors for measurement of the pool water quality are described in this section. Lastly, sensor convertors, power supplies, pump controls circuit and display interface are described here. The key section of the thesis is the design description which consists of hardware, mechanical and software section. It starts by the description of the printed circuit board with a description of diagram. In the section followed is described and illustrated mechanical design of the box for this dosing equipment. It is my own design made by 3D print. The last design section deals with software consisting of three different kinds of software: display software, ESP32 microcontroller firmware written in C/C++ and HTML code of the webside. This description is focused especially on the firmware architecture of the processor ESP32 related to consecutive part including description of a local user interface as well as a web application. The resulting device was developed to the state with matured well tested user interfaces. However, the controls algorithms of pH and ORP were tested only in simulated conditions. Therefore the testing in real pool for verification of the firmware and reliability should be done in the next steps