UART Serial on RPi 4B
---------------------
date: 2025-05-30

There's 22 pins on this board; With the strip
on the pins on the top right, we want the
following:

+-----------------+
|              xx |
|              xx |
|              xG | - (GND) Ground
|              xT | - (TXD) Transmit
|              xR | - (RXD) Receive
|              xx |
~~~~~~~break~~~~~~~
|                 |
+-----+-----+-----+
| USB | USB | ETH |
|     |     |     |
+-----------------+

On my connector, GND is black, TXD is white
and RXD is green. Red is Power, but that's not
needed here (the system should be powered on
via the usual USB-C).

On OpenBSD the command to connect is:

# cu -l cuaU0 -s 115200