The long press already reached board.powerOff(), but nothing armed a wake
source, so the board stayed dead until a reset or a USB reconnect. Arm the
user button (pull-up + SENSE_LOW) before entering SYSTEMOFF, after waiting
for the release: SENSE is level triggered and a still pressed button wakes
the board up immediately. If the button is never released, reboot instead:
SYSTEMOFF would wake up right away anyway, so make the reset explicit.
GPIO output latches survive SYSTEMOFF, so shut the switched rails down as
well (GNSS, RGB led supply, EEPROM, battery divider, EN1/EN2, PWR_EN), in a
shutdownPeripherals() override so they go down after the radio and the GNSS
receiver. Give pins 36 and 34 a name while there.
Tested on a ThinkNode M3 companion_radio_ble: a long press powers the board
off (the USB device disappears and stays away), a short press brings it
back, and holding the button past the timeout reboots.
Ermanno Baschiera
adb93565e0