pub const fn from_adv_matrix(row: u8, col: u8) -> Option<Key>Expand description
Maps a TCA8418 matrix position on the Cardputer ADV to its key.
The ADV wires the 4×14 keyboard as a 7×8 matrix: each scanner row drives
two adjacent physical columns, and scanner columns 0–3 / 4–7 select the
physical row for the left / right one. (Wiring per the ADV schematic
and M5Stack’s M5Cardputer library.)