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I want to control 4 led s using switch. I pressed switch one time first LED is turn on. after some time another led s are turn on/ off one by one. the delay is not mentioned.

how ever I want to get status of led. which is the turn on led now?

What I have tried:

without using sensor, how to do that?
Updated 20-Mar-17 2:23am
[no name] 20-Mar-17 8:13am

1 solution

Just track the status within your program using a variable:
Whenever a LED is switched on or off by your program set the status variable accordingly.

The above requires the state to be known when starting the program (e.g. by switching all LEDs off).

As an alternative read the pin state of the LED ports using digitalRead(). This will work also for ports defined as output.
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SandiT 21-Mar-17 14:16pm    
Thank You very much.

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