Sound detected countdown timer?

[melk76]

Hi guys, I'm trying to create a project that when activated by a sound, starts a countdown and then sounds an alarm (about 5 mins - pulsating one using a 555 timer) and can repeat.

Or, if the time delay can decrease (between each alarm) after each run. Ie -

Sound detected, Countdown starts, Alarm sounds, (back to countdown start, if possible 'take 1 min' )

Thanks so much for any help!! I'm so confused lol, I've realy got no idea about values etc. So I'd be SO grateful for any help!! All the best,


(I've added a block chart for it if it helps )

 

[davenn]

hi there,

google is a wonderful thing always a good place to start

just an example... try here they have a bunch of timer ccts maybe one will suit your need or form the core of what you want to do

http://www.electrokits.com/Sound-Activated/Voice-Activated-Switch

Dave