I'm trying to make a cable checker to help me make custom cables for my computer. I'm thinking I plug the cable ends into sockets on the device, then the Arduino checks between different pins to make sure that no wires are in the wrong spot or unplugged.

So I'm thinking it runs through like this:

tests pin 1 - 2 to see if they're connected, if yes, light up a green LED, if not, light up a red LED

tests pin 3 - 4, does the same thing

Repeats this for every wire in the cable

Am I on the right track? How would I do this? I've seen people talking about pullup resistors but I'm also seeing people say that shorting can damage the board