This work presents the development of a low-cost technological solution aimed at automating access control to a university cafeteria in a public educational institution. The proposed system is based on the Internet of Things (IoT) paradigm and uses barcode reading from student identification cards combined with communication via the MQTT protocol. The solution is designed to operate with limited hardware and network resources, ensuring efficient, reliable, and scalable data exchange between devices and a central server. Currently under development, the system seeks to provide accurate records of user access, supporting improved demand estimation, reduction of food waste, and optimization of institutional resource management. The proposed approach highlights the potential of lightweight IoT architectures to enhance operational efficiency and sustainability in academic environments.