NFC competition PCB

We are students from the student association of Electrical and Computer Engineering at the Eastern Switzerland University of Applied Sciences. OST is the university of applied sciences for the six cantons of Eastern Switzerland and the principality of Liechtenstein. With around 3800 students spread across six Schools, 1500 professionals pursuing executive education, and over 1000 current research projects, the OST is Eastern Switzerland's regional educational hub.

Each semester, we organize a special event for all students in the Electrical and Computer Engineering department. The “E-Abend” has long been a tradition, offering students a chance to network, exchange ideas, and build lasting connections in a relaxed setting. To make this year’s event even more engaging, we decided to introduce a soldering competition. A test of precision, efficiency, and technical skill. This project was developed as the foundation for that challenge.

At the heart of our design is a Dynamic NFC/RFID (ST25DV04K) tag IC paired with an ATtiny402 microcontroller. This combination allows the PCB to function as an interactive NFC tag, which can be scanned by any modern smartphone. The microcontroller continuously updates the content stored in the NFC IC, allowing for dynamic and responsive interactions. The number of different messages that can be stored and modified is limited only by the microcontroller’s available memory, making it a flexible and adaptable system.

Throughout the development process, we encountered several technical challenges. One of the most significant was the power constraint inherent to NFC-based systems. Since NFC does not transfer large amounts of power, the microcontroller must operate under strict efficiency requirements, running at reduced speed and with optimized code to ensure stability. Another major challenge was designing an NFC antenna/coil, as the efficiency of the energy harvesting by the IC and the data transmission depends heavily on coil geometry and tuning.

Additionally, we had to carefully manage interface arbitration between the RF (radio frequency) and I²C communication channels of the NFC tag IC. Since the IC allows only one interface to be active at a time. The microcontroller must monitor and wait for the RF link to be disengaged before initiating I²C communication. This required precise synchronization to ensure smooth operation without conflicts.

Another demand of our project is that we can quickly program many of these tags, so the competition can run smoothly. The solution we came up with is a programming jig. The interface to the PCB is created with pogopins that are embedded into the 3D printed frame. This programming construction has also been helpful for debugging purposes.

Despite these complexities, the project proved to be an extremely valuable learning experience. Not only did it push us to refine our understanding of embedded systems, low-power electronics, and NFC technology, but it also resulted in a fun and practical application that will serve as an exciting test for students at our event. The PCB will allow us to quickly determine the most skilled soldering student while adding an interactive and competitive element to the challenge.

However, as a student-led initiative, we face financial limitations. Our goal is to make this experience accessible to all students in our department, which requires producing approximately 125 PCB's. Given these constraints, we would be incredibly grateful for PCBWay’s generous support, which would enable us to bring this project to life and provide an engaging, hands-on learning opportunity for all participants.