Remove arduino from sleep without using interrupt

Hi,
I just wanted to know how can I remove the arduino from sleep mode without using any external interrupts, I have connected a Keyboard to the arduino I want the arduino to wake up when any of the key is pressed on the keyboard

Without using interrupt, or without using external interrupt? This are two very different questions.

In the first case: use the reset function.

In the second case: use one of the many many other interrupts (timer, pin change, analog comparator, …) the Arduino has available.

I have connected a Keyboard to the arduino

What kind of keyboard? Connected how?

PaulS:
What kind of keyboard? Connected how?

4*4 matrix keyboard is connected

wvmarle:
Without using interrupt, or without using external interrupt? This are two very different questions.

without using external interrupt

wvmarle:
In the second case: use one of the many many other interrupts (timer, pin change, analog comparator, ...) the Arduino has available.

can you just show me an example how can I use pin change to come out of sleep

Thanks and Regards
MaazSk

Try a site search on 'wake pcint'.

4*4 matrix keyboard is connected

That would be a keypad, not a keyboard.

Look at the keypad library, to understand what the Arduino has to do to determine if a key is pressed. Ask yourself whether the Arduino can really do that while asleep.

PaulS:
Look at the keypad library, to understand what the Arduino has to do to determine if a key is pressed. Ask yourself whether the Arduino can really do that while asleep.

The keypad library may not support it, but otherwise I don't see a problem. Set ALL columns to LOW, PC interrupt on the row pins, and the Arduino will get an interrupt when any button is pressed. When awake it can try to figure out which button it was.