I am working on an electronic chessboard that connects to Lichess. The board should be able to detect any chess position at any time, so I cannot rely on move tracking. For this reason, I chose NFC to identify each piece using tags.
I am currently developing a cost-optimized and low latency hardware architecture for this project.
With the help of @Travis Palmer , I completed my first prototype PCB, which includes 4 antennas and analog multiplexers as described in application note AN6121. Using this approach, I would need 64 antennas, 64 multiplexers and multiple NFC readers for low latency, which is quite costly and complex.
Travis suggested an alternative keypad-style antenna matrix layout with 8 row antennas and 8 column antennas (total 16 antennas), as shown below:
I understand that with anti-collision it is possible to detect multiple tags on the same row or column. However, I do not understand why the antennas should overlap. Wouldn’t it be better if the antennas do not interfere with each other, so that each piece is detected by only one row and one column antenna?
Thanks in advance for answers or design ideas! :)
