This project is formed by  a Chrono Controller (with a small 7-segment viewer), and a 5,6" 7-segment Digit Viewer.It allows you to program a certain time (Mins & Secs), and start the time counting it back.Also when the counter gets to 30 secs, it activates the relay for 1 second. it does it for 3 seconds when the time arrives to zero.The time is transmitted through Serial (9600) wires  (GND+TX), and could be showed by a serial array of Viewers.

Its very simple to build.
All the elements are well detailed on FZZ files.

 

IMPORTANT: It needs a 9V power supply

 

WATCH THE VIDEO OF COUNTERCHRONO