What is the pinout of the Arduino MKR motor carrier when using external power supply, not the Li-Po battery
Vin means &quot;Voltage Input&quot;. That's where you provide your power. That is the input to the voltage regulator.
5V and 3.3V are what the board uses internally and are provided for you to also use should you want to. These are outputs from the voltage regulators.
It's exactly the same (though more efficient and higher current) as almost every other Arduino.