lets make a pcb for a matrix-logic cross-word-boardgame with 13x13 fields with a rasberry pico 2 micro controller. Each column of the game has 5 signalcords, with one GND cord between them. These signalcords and GND are connected to 13 connectors on the board f.ex (lcsc C46061759). Pin, 1, 3, 5, 7, 9 of theese connectors ar connectet to 8 daisy-chained shift registers (75HC595). Pins 2, 4, 6, 8 to GND.

Each row of the board has 1 receiving singnal cord (and a parallel GND-cord) connecte to the pcb over 2x 12 pin box connectors. pins 2, 4, 6, 8, 10, 12 are connected to 2x shift registers (74HC165).

the two daisychains are connected to the pico 2 pins 1, 2, 4, 5, 6, 7.

on the pcb there should be a USB-C connector providing power with a switch (on/off).