Wake and sleep

HI guys,

I have my andruino which takes temperature and moisture, sends them by Nrf24. It works.
Now I would like to have my adruino wake every hour, take measures and sleep. It will be powered by battery (3.7v)
how can I tell my arduino wake up every hour.

Thanks in advance for your answer.

HI Tack,

This post is perfect!
I have found the Watchdog function but is there a "timer" for 1 hour?
Of course with low consummation? Do I need to add a component and plug it to the Digital2 pin and using interupt?

Regards

http://code.google.com/p/narcoleptic/
https://www.inkling.com/read/arduino-cookbook-michael-margolis-2nd/chapter-18/recipe-18-10
"To sleep for longer periods, you can repeat the delay intervals until you get the period you want:"

You could also try this library:

Thanks Guys,

I will have a look at these librairies.

Regards,