I have a very simple setup with a wave shield, power amp (http://www.maplin.co.uk/40w-power-ampli ... dule-37737
), PIR and an Arduino duemilanove running a simple, button switch plays random file program. I am Powering all this off a 12v 7Ah sealed lead acid battery.
This all has to be in situ up a tree, triggering when people pass. Because of its inaccessibility, I'm trying to reduce power consumption and have the system shut down at every opportunity. I have been looking at the Sleep mode code but I believe this is only effective on the Arduino chip.
Is there an effective way to power the PIR independently having it switch on the rest of the system (amp, Arduino, waveshield) when activated? Could this then be powered off when the file playing on the Waveshield finishes? Or would a better option be to make what power savings I can on the Arduino with the sleep mode code, as the Amp and inactive Waveshield draw very little power anyway?
Your thoughts would be appreciated.