MegaMute is an over-engineered mute button with an inspection / SCADA style monitoring only (via bluetooth or usb serial) of a relay latch lock-out key/remote/master and XLR jacks that are connected/disconnected physically.
Designed for Sparkfun Arduino Pro Micro 5V/16Mhz and a BlueSmirf bluetooth module. (TODO: links) 4 5V Logic IO lines for: