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Comment by knodi123 | Hacker News Reader

> The Capture LED lets others know when you’re capturing content or going live. If the LED is covered, you’ll be notified to clear it.

Wonder how that works. Maybe the capture LED has a light sensor next to it that detects reflections? It solves an interesting problem, although the prevalence of cheap spy camera glasses on amazon make it an uphill battle.

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LEDs can effectively be used as light sensors when wired in reverse - About a decade ago there was a post where someone turned an 8x8 LED matrix into a touch sensor.

Edit: Found the link, here it is: https://mrl.cs.nyu.edu/~jhan/ledtouch/index.html

Analog Devices has an excellent article about using LEDs as sensors in this way: https://wiki.analog.com/university/courses/electronics/elect...

It’s probably duty cycled on and off and compared to a photodiode output on the reflection.

Either way the moment that light comes on you’re getting punched if you point it at the wrong person. I’d rather have my phone hit out of my hand. Google Glass was not welcome and I suspect the same will be true of this.

> Either way the moment that light comes on you’re getting punched if you point it at the wrong person.

Seems not worth worrying about.

They could pulse the LED quickly and while it's off use it as a light sensor for ambient light.

I wonder if one could just replace the LED with a UV one, depending on the tolerances this kind of detection may still work while being visibly "off". :/

Probably this. Doing so would allow one to check for agreement between the video feed and the light sensor.

I'd presume via the same type of proximity sensors that disable your phone screen when it's held to your ear

That wouldn't work with all materials that could be used to cover the camera. The proximity sensors that you describe are designed specifically to measure the change in capacitance due to proximity to a human; they can't detect something like a blob of glue that causes no change in capacitance.

For some reason this really doesn't work for me. I have also enabled the extra feature of locking the touch screen when in dark places, too. I still regularly get my pocket navigating my browser and my ear starting songs on Spotify mid-call.

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