Design of a Dynamic HMI–PLC Prototype for Coffee Bean Roasting Profile Control

The coffee roasting process lacks standardization because key organoleptic attributes depend on manually set time and temperature parameters influenced by bean characteristics and operator experience, introducing variability and human error into the control of the roasting profile. This research aims to design and validate a PLC-HMI-based prototype with a dynamic interface by identifying requirements, developing automation electronics, implementing a PID control algorithm, and creating an HMI to automate and control coffee bean roasting profiles. The methodology involved the design and implementation of an automated temperature control system for coffee roasting through requirements definition, electronic design, hardware-software integration, and experimental validation. The development was structured according to the VDI 2206 standard and focused on the roasting stage under controlled conditions. The results show that the control system achieved stable monitoring of the thermal profile with validated PT100 measurements, maintaining consistent control of the setpoint with an approximate error of 5% in repeated tests. The main conclusion is that the proposed prototype effectively reproduces the controlled roasting profiles, although future improvements, such as the integration of a cooling stage, are required to optimize test efficiency and expand the system's evaluation.