So first, take this basic design, and make it a security keypad for ST with the ST shield.
They key difference:
Your code to disarm ST wouldn’t be a numerical code, but a directional code like “up up down left up”
What the arduino would do is every time you wake up the keypad, it lights up a random key and you click the button adjacent to it according to your directional code. It would then light up the second random key, and so on. If the key that lights up is on the edge, you would wrap around to the other side of the keypad.
I was thinking this would make it harder for onlookers to snag your code.
…yea, my brain doesnt think inside the box, or even know what the box is made of