eli5: when a 5V signal is attached/applied directly to an input pin on an arduino, does that input pin act as ground?

Question

For example, when a push button is pressed. The 5V supply connects to the signal cable, which is attached to Pin 2, for example.

But where does the current ‘sink’ into? Doesn’t it need an explicit ground pin? If it goes right into Pin 2, is that the ground pin in disguise?

Or is the signal pin (pin 2) the one applying the current through the push button..?

In: 0

Answer 1

The input pins are connected to devices called “Analog to Digital Converters”. They transform the voltage level on the input pin into a digital value that the Arduino understands. The ADCs have a connection to ground.