Workplace Pest Panic Button

I now have a working PCB prototype with the attiny84 instead of an atmega328p.  I've posted both the board layout and source code.  I decided to use an attiny84 to reduce the footprint but in hindsight for my future goals on this project i may go back to using the at328p or some other AVR micro.

I have a working breadboard version with an atmega328p.  I am testing this device against a cisco vg224 voice gateway with default settings on the line port.  The cisco gateway only puts out 38VDC rather that your typical POTS line from the phone company at 48VDC but I think I should work with that as it would be typical of an office environment.  I plan on porting my code to an attiny84 for a smaller footprint.  Once I make a working board layout and test the ported code I will submit it for sharing.