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OS X Mavericks Taps Ambient Light Sensors to Detect Motion and Prevent System Sleep

energy_saver_preferenceOS X Mavericks includes a new feature that leverages the light sensors included in many Macs to detect movement in front of the machine and prevent the system's Energy Saver sleep functions from activating even when the user is not actively using the machine, notes The Verge.

First highlighted by Moshen Chen of Radiantlabs and confirmed by developer Jonathan Wight, the feature was initially thought to use the iSight camera to monitor movements but was quickly discovered to actually be tapping into light sensors.
The sensor is already used to adjust screen brightness to ambient light, but the new OS puts it to a different purpose, tracking changes in the light as "movement," and resetting idle time accordingly. Verge tests confirmed this on two separate Mavericks laptops: after covering the camera but not the light sensor, we were able to delay sleep mode by changing the ambient lighting conditions.
Users have long been able to set separate thresholds for display and system sleep based on lack of interaction with their Macs, but under Mavericks, many Macs have now become smarter about being able to detect whether or not the user is sitting in front of the machine.

Top Rated Comments

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15 months ago
How about we have the Mac not go to sleep when you're downloading something or encoding a video?

That would be really helpful.
Rating: 23 Votes
15 months ago
Dave?

Dave, are you awake?

"Ugh, just go to sleep."

I'm sorry, Dave. I can't do that.

Why are you not typing on my Dave?

I know you're awake...
Rating: 22 Votes
15 months ago

How about we have the Mac not go to sleep when you're downloading something or encoding a video?

That would be really helpful.


this doesn't help?
Rating: 19 Votes
15 months ago

How about we have the Mac not go to sleep when you're downloading something or encoding a video?

That would be really helpful.


Well, ask your application developers to use power assertions.
Rating: 10 Votes
15 months ago

How about we have the Mac not go to sleep when you're downloading something or encoding a video?

That would be really helpful.


Here's my FAVORITE simple Mac app:

http://caffeine.en.softonic.com/mac

It puts an icon in the task bar that toggles on a 'no sleep mode' when you want it.
Rating: 9 Votes
15 months ago

this doesn't help?


It should automatically disable sleeping in those cases though.
Rating: 6 Votes
15 months ago
Hurray for push notifications! Now what's the article about?
Rating: 5 Votes
15 months ago
I hope this sensor isn't "racist" like the HP webcams...

http://www.cnn.com/2009/TECH/12/22/hp.webcams/ (http://www.cnn.com/2009/TECH/12/22/hp.webcams/)
Rating: 4 Votes
15 months ago

Download Caffeine


Like this?

Rating: 4 Votes
15 months ago
After I seen this article, I decided to test it out a bit. I set mine to sleep after 1 minute. Just sitting and looking at the screen without touching anything kept it awake. I wasn't moving around a whole lot. I was trying to stay as still as possible, but it picks up the slightest movement, which is good. I sat for about 3 minutes and the screen stayed on. I stood up and walked off to the side, out of view from the sensor but where I could still see the screen. It dimmed after 10 seconds, and went to sleep after 20. This means the timer does not reset and begin counting after it stops sensing movement. If you don't use the computer at all after your time is reached, it won't shut off until it stops sensing you sitting there. Basically, the timer starts counting after the last physical interaction with the computer, but won't begin sleep mode until you walk away. Very neat and well designed.
Rating: 4 Votes

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