Work Mode arduino nano 33 IoT:D0 ↔ pump:VCC arduino nano 33 IoT:GND ↔ pump:GND arduino nano 33 IoT:A0 ↔ FC28:A0 arduino nano 33 IoT:GND ↔ FC28:GND arduino nano 33 IoT:3V3 ↔ FC28:VCC