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How do the buttons (like A, B, X, Y, and D-Pad) on game pads (such as the Xbox controller) interact with the PCB? If my question sounds vague, refer to the pictures below:
Are A/B the same as C/D? In game, the D-Pad (left) shows up as "Axis", while the buttons (right) just show up as "button".
What are A/B/C/D called, and what are they made of? It all looks and feels like rubber, but if that were the case then it wouldn't have any effect on the electrical properties of the PCB in that area (right?).
How does the logic of A/B and C/D work? How does B pressing on A (or D pressing on C) send a signal to the computer saying "button X has been pressed"/"D-Pad UP has been pressed"?
For reference, I know how a push-button works; it makes and breaks physical connections, which in turn impedes or allows electrical current to flow. But I can't see how that happens in this picture.
Also, here's a picture of the other side of the PCB (it might help).