U403: change from 74LVC2G125 to 74LVC2G126 The two parts have the same footprint and pinout, but '126 3-state buffers have active-high OE inputs instead of active-low. The change is purely for software benefit: having GPIO 11/12 set to 1 correspond to that current contribution being enabled will be much more intuitive for developers and tinkerers.

/* battery or power supply connector */

module battery (VBAT, GND, Third_pin);

output VBAT, GND;
inout Third_pin;

conn_3pin batt_conn (.pin_1(VBAT),
		     .pin_2(Third_pin),
		     .pin_3(GND)
	);

capacitor big_cap (VBAT, GND);

/* VBAT tap for calibration measurements */
header_2pin vbat_tap (VBAT, GND);

endmodule