I bought a couple of small screens to test from EarthLCD. (The guy I spoke with on the phone was an asshole. Just saying.) The screens are about 5″ each. One is black & white and one is color. The plan is to test these out, and buy more of the one I like better The following are short tests with the screens. Eventually…these will go on my face.
What’s happening: The two camera’s respective signals are being sent across a DPDT (Double Pole Double Throw) relay. One signal and one ground to separate poles on one side. When the relay is thrown either way, one of the two camera’s signals is connected and the image shows on the screen. The relay is being triggered by a lower voltage (5VDC) relay which itself is being thrown by pulling a pin high on an Atmega8. The Atmega8 is reading analog data (pulseIn (Arduino)) being transferred from an Xbee wireless module whose pair Xbee is doing an analog read of a Piezo sensor.
Basically. When the Piezo is shaken enough, the camera is switched. A debounce function is thrown in for good measure.