I use the Adafruit Library to connect both devices. It is pretty clear and has really clear examples on how to do this. In some cases an extra wire for IRQs is needed. See diagram below

The zones of the field are detected by means of Photo-diodes present in certain spots on the Duel Disk. This Photo-diodes are activated by light outputing a certain voltage. This voltage can be read by an ADC on the Arduino and processed via a threshold or by a digital pia as either a HIGH or a LOW.

There are 17 Photo-diodes to detect in the 12 zones in the field.

Additional coding has been made to accommodate the timing of how the player places the card, since one player can take more time to place the card.