The Four-Pin Switch: Hooking it up

So in the past few projects that I've worked on, I've been using a four-pin switch, and I hadn't thought about how to connect it until well that moment, so I thought I'd break up the XBee smorgasboard of posts with one about my four-pin switch!

Okay so 4 lovely pins, but how do you know which pins go where? So usually, you have to monitor a specific pin on your microcontroller which lets your program know when the button's been pressed, or not.  Or if it's all analog, when you click down the button, you're completing a circuit.

But this still doesn't answer WHICH pin.  So what happens is you'll need your multimeter. 

When the button is not pressed, the following are electrically connected (zero resistance):

But when the button is pressed, the following are electrically connected:

Here's an example of one way to connect this such that Pin 7 will notice the pushbutton being pressed when ...pressed :p.

Example 1:

Button not Pressed:

Button Pressed:

Example 2:

Button not Pressed:

Button Pressed:

Note - take care to note if you put the switch on one side of a breadboard with no electrically isolated space between the pins, that you may end up getting pins electrically connected even when you don't want them to!

@atdiy/@tymkrs