1Core Memory Shield with LEDs
1) 3D Print the LED to Core light guide, and optionally, a stylus.
2) Install the firmware on the Uno.
3) Connect three wires (5V, GND, Signal is D14 [A0]) from Uno to Featherwing. The text "Core Memory" should be scrolling.
4) Stack the Core Memory shield on the Uno and supply discrete 3.3V to the shield. Ground is already common through the stacking headers.
5) Connect a button between Uno Digital D12 and GND.
6) Glue the magnet into the stylus or use another magnet/stylus combo.