RS232-TTL

The circuit implements a power supply either via a direct 5V supply (X6), or via a switching regulator (X2). A large part of the circuit consists of the components for the Arduino. The MAX232 (K3) is needed for the translation from RS232 to TTL, so that the PLC can communicate with the Arduino.
The nRF52840 (K6) acts as a BLE interface. 
The board as a whole is used to control the LED's of the game pieces, to receive the data from the dice and to provide an interface to the PLC.