Please note: Although this question tangentially involves a Raspberry Pi, this is really more just a pure electronics question at heart.
I'm trying to connect my Raspberry Pi 1 Model A to this pushbutton. I believe my pushbutton will be wired to the voltage source (
PWR) which is a 5V pin on the Raspberry Pi (hereafter RPi) as well as to a 3.3V input pin ("GPIO pin"). When you push the button, it's contacts touch and connect the circuit/path between the RPi's
PWR pin and an input GPIO pin...I think that's how its supposed to work.
I've also seen wiring diagrams of this in action, and believe I need to put a resistor in between the pushbutton and the input GPIO pin. If this is incorrect, or if the resistor needs to be placed somewhere else, please begin by correcting me!
My question is: how do I calculate the required ohms of the resistor? This particular pushbutton is rated at 12VDC at 500mA.