I'm somewhat new to the hardware side of electronics, and need to build something with ALOT of momentary switches using the Arduino. I'm poor enough that even buying a bunch of momentary switches is going to make a nasty dent in my wallet. However, I've seen people use nails and other bits of metal as crude electronic interfaces, and I want to know whether this will work.
--- My Idea ---
Take something conductive. Like a nail. Connect (low, preferably) voltage to it, and then add a pullup resister going from the nail to an I/O pin. When nothing is touching the nail, the I/O pin should be high because the electricity has nowhere to go but through the resistor, but when my finger presses the nail, the electricity follows the path of least resistance down my body into the ground. The I/O pin goes low, signifying a touch.
I figure if all I have to buy is an LED driver, some LEDs, and some multiplexing chips, I can make something similar to a Monome for about 50$ using some spare acrylic/plywood and some metal contacts. But that only really works assuming that my idea isn't completely stupid and won't result in a dead Arduino.
Other benefits are that the construction will be infinitely easier, neater, and more durable this way. Metal contacts won't get nasty, or stuck, or break. It's going to be part of my live performance rig, so this is really ideal.
P.S. I know about capacitive sensing, but it's going to be slow for over 64 contacts. I would prefer to do things this way.