I want to put my Arduino to sleep ( achieved) and then I want it to wake up every few minutes ( or less) check the value of an input and then either go back to sleep or fully wake up.
So somethink like.
mv1=analogRead(PPO1pin)
if mv>=523 wakeup
else sleep
How do I do this?
Anyone?
There is an example of how to wake the arduino out of sleep mode via WDT here: http://interface.khm.de/index.php/lab/experiments/sleep_watchdog_battery/
Another option I would consider: use a hardware comparator with your desired reference (apparently 2.56 volts, in your case). Then put the arduino in sleep mode, to be woken up by the interrupt from your comparator. This has the advantage of being immediate, and easier to code, but it requires some (very small and cheap) extra hardware.
I did a post a while back about putting it to sleep for 20 seconds and then checking a clock:
Excellent, Thanks guys will dissect the sketch and put it to use.