I'm confused as to how an active-low push button detects a change in voltage. Below is a model of a conventional setup of one of these buttons I found.
When the switch is open (like in the image), there is some current, I, flowing into the MCU.
But when the switch is closed, wouldn't the current just flow to both the GND and the MCU like in a parallel circuit? (because the electrons have the same amount of potential energy so the voltage is still the same?)
If so, how does the MCU detect when the button has been pressed if there is constantly current flowing into it?
I'm a novice with microcontrollers and electronics, so please don't hesitate to point out the obvious!