Krzysiek91:
now I have problem bcs sleeping mode don't remain as long as I want.
The length of time it sleeps for does not matter. Suppose it sleeps for 1 second then wakes for 5 millisecs. That means it is asleep for 99.5% of the time. If you want to "sleep" for a minute just increment a counter every time it wakes up. If it wakes every second then when the count gets to 60 a minute will have elapsed.
...R