" (32) GPIO 12 " " " " " 1kΩ " " " " " " LED1 " (34) GND " (36) GPIO 16 " " " " " 1kΩ " " " " " " LED2 " (38) GPIO 20 " " " " " 1kΩ " " " " " " LED3 " (40) GPIO 21 " " " " " 1kΩ " " " " " " LED4 " " " " " " GND " " " "