blinkinlove-materix/config-example.h

#define DEBUG true

// [If you haven't done so already] copy config-example.h to config.h

// When DEBUG is true, board's MAC address is printed to serial
// Once you copy MAC addresses of both mates, use them as YIN/YANG below.
// You can then upload the same code to both mates (each would know to
// scan for the other one, and not for itself).

#define YIN "11:22:33:44:55:66"
#define YANG "ff:ee:dd:cc:bb:aa"