Power Indicator Light during sleep mode

A very quick question that I can't find the answer to in the Datasheet or online, and my eyes are getting sore now.

Is the Power On indicator LED supposed to stay lit when the Arduino is in Power Down mode for Sleep ?

If it is, then is there a way to shut it off to save even more power during sleep mode ?

I already do the the following:

Disable ADC
Turn off power to ADC / Timer 1 / Timer 2 and the Serial Interface
Put OUTPUT pins to INPUT during the Sleep period
Disable BrownOut detector

The only indication that the system is powered up in any way is the Power On light. If it's hard wired and can't be disabled during sleep, then it seems a waste of current as the project is in a closed case where the Arduino cannot be seen from external to the case, so the Power On idicator during sleep is a bit of an oxymoron.

Any ideas ?


Which Arduino?

The Uno is not intended to be in a case or to save power during sleep.

Something like a Pro Mini or Micro is better for power saving but you still have to desolder or destroy the power LED.

My crystal ball sees a Digispark.


Cross-posters are time wasters. Best to ignore.

For Wawa - You are correct in that the link you posted was to a thread I started specifically regarding the Digispark. However, this project concerns the Uno which I find easier to play with when designing projects. If I get a project running on an UNO, I rewrite it for cross platfrom use and transfer to a NANO or Digispark or a straight ATTiny85 bare bones.

What I don't do is advertise my e-peen size by insulting people who are asking a genuine question. The original post in this thread specifically stated the UNO but maybe I should have indicated the final version on a NANO. Either way, the question was about the Power On light.

What I didn't ask was, "Which one of you big headed oafs wants to gain Karma points by name-calling somone with a genuine question?".

To all the reasonable people out there ( What the heck are you looking at, Wawa ), it appears the general concensus is that I have to desolder the power led. Thank you to the people who recognised the genuine nature of the original post and came back with constructive replies.

Oh! and Wawa, if you are using a Crystal Ball in this day and age, might I suggest upgrading to a Magic 8 Ball, you may be able to interpret what people are asking in a much better way.

The original post in this thread specifically stated the UNO...

No, it does not.

When you don't mention which Arduino, someone trying to help is going to look at your previous threads for clues.
There we find two more threads about the same subject (sleep mode), using a Digispark.

Indeed it's not mentioned what Arduino you use, and considering you want to go low power the Uno is possibly the worst choice. Removing the power LED will help a bit - but you still end up with some 30-40 mA of current wasted in other parts.

Start with a Pro Mini if you want to go low power. Remove the power LED and the regulator from that board and you can quickly go down to the uA range, about the same as going barebones.