Coffee Maker Monitoring System

The graphical user interface (GUI) in this project is built using Qt and runs on a Raspberry Pi 5, providing a real-time visual dashboard for monitoring espresso extraction. It displays key brewing parameters such as water temperature and pressure, updating dynamically as data is received. The GUI fetches this data live from an ESP32 microcontroller, which transmits sensor readings. These values are processed and visualized through responsive graphs and statistics, allowing users to track brewing performance and ensure consistent coffee quality. Users can also view historical data stored in the database. The database is used for seamless storage and formatting of incoming datastreams. It also acts as a middleground between the sensors and the User Interface. The ESP32 is used as a traffic officer to ensure that all sensors are read accurately and efficiently. By applying real-time principles, the ESP32 prioritizes time-critical tasks, manages sensor communication with precise timing, and ensures that reliable data is transmitted to the Raspberry Pi.

The electrical subsystem uses an ESP32 to collect real-time data from I²C pressure sensors, RTD temperature sensors, and analog sensors via external ADCs. This setup accurately tracks brewing parameters like temperature and pressure, enabling real-time monitoring to ensure coffee quality. We have chosen to make a PCB that is designed to work with the ESP32 microcontroller. The plan is to house the PCB within the espresso machine itself, and let it communicate wirelessly to a Raspberry PI 5 in the near vicinity. The PCB´s function is to take incoming signals from sensors, and send the information to the ESP32 and then further. A ESP32 is going to be mounted on the PCB itself. The PCB is also designed with some lowpass filters, so that some of the sensor data is filtered. The PCB will also have a RTC inbuilt into it, just in case that the system goes offline, so that we are able to track the date and time.

The Faema Due D92 espresso machine uses a heat exchanger system, where a large boiler remains constantly hot, and cold water is rapidly heated as it flows through a metal tube inside the boiler before reaching the grouphead, ensuring fresh water is used for each shot. This system, supported by a powerful electric pump and manually controlled valves and solenoids, allows for simultaneous brewing and steaming while maintaining consistent thermal stability and pressure.