Datasheet

VCC: This pin outputs 3.3V through the on-board voltage regulator. This voltage is 3.3V if USB or VIN is
used and equal to the series of the two batteries when they are used
LED ON: This LED is connected to the input voltage source from either USB or VIN. It is also connected to
the battery power. This means that it is ON (with a lower intensity) also when the battery is inserted.
Onboard LED: On MKR GSM 1400 the on board LED is connected to D6 and not D13 as on the other
boards. Blink example or other sketcthes that uses pin 13 for on board LED may need to be changed to
work properly.