Using a pre-loved Telechron 6-digit 7-segment clock, controlled by a MAX7219 IC…

On power up.. clock to display  00 00 00

if Digital I/O xx is HIGH (pulled to 5v) (requires external pull-up-resistor)

counter = 1 hour.  ** Closed contact closed, or button pushed..

Counter is always counting down

When clock gets to 00 00 00, stop counting.

Closed contact from Brightsign Relay box, when clip starts – timecode 00h00m00s00f  for 2 seconds.. tells clock to start counting down.

Code: https://github.com/dargs/timer

Parts:

1x ATMega168

1x 16MHZ Crystal

2x 22pF Caps

10k resistor (reset pullup)

10uF cap (decoupling)