Never let it be said that us engineers don't do culture - the title is a quote from Shakespeare, just in case you don't recognise it [Love's Labour's Lost] - so I've come up with this light post in his honour and memory.
Now I know what the IO pin looks like (electrically) I can light up an LED. In fact it's trivial, because the series resistor on the board will do for the current limiting. So here we have a micro:bit flashing a red LED. (You'll have to trust me that it's flashing. I took a video but it's too big to upload. I'm sure you all know what a flashing LED looks like, anyway.)