Use buttons to provide external inputs to the microbit.
A small push button can be used to provide an external input into your circuits.
This is a small, SMD-mount tactile switch identical to the ones on your microbit. These switches are normally open (or NO) and so must be pushed to close the circuit. It said to be momentary as it must be held to close.
One of the button’s pins is connected to 3V. The corresponding pin to
pin0 of the microbit. When the button is pressed,
Published: December 23, 2016 Updated: December 23, 2016
Acknowledgements: SMD push button switch by Sparkfun (CC-BY-2.0)