Pins

The micro:bit has 25 external connections on the edge connector of the board, which we refer to as ‘pins’. The edge connector is the yellow area on the right side of the figure above.

There are five large pins that are also connected to holes in the board, labeled 0, 1, 2, 3V, and GND. Along the same edge, there are 20 small pins that you can use when plugging the micro:bit into an edge connector.

Of the 5 big pins, 0, 1, 2 pins are signal pins. The 4 pin (3V) is for power, connecting to the + of a battery. The 5 pin is for ground connection, connecting to the – of a battery. Electricity has to flow from power pine to ground pin in order to drive things.

There are mini pins between those 5 big pins. They can be used to control more devices.