How do the camera and microphone switches work?

After peeling back the bezel, I noticed that the camera and microphone switches appear to use these strange non-contact switches that I’ve never seen before.
I can insert plastic and paper into the switch, and it will turn off the camera, but my fingernail doesn’t appear to work.

I ask this question in trying to figure out if these are actual hardware switches that cut off power, and not software switches.
dmesg | grep -i "Camera" indicates that they’re hardware switches though.

[ 4998.238002] usb 3-7: Product: Laptop Camera
[ 4998.241301] usb 3-7: Found UVC 1.00 device Laptop Camera (0bda:5634)
[ 4998.247012] input: Laptop Camera: Laptop Camera as /devices/pci0000:00/0000:00:14.0/usb3/3-7/3-7:1.0/input/input57
[ 5008.988008] usb 3-7: Product: Laptop Camera
[ 5008.991308] usb 3-7: Found UVC 1.00 device Laptop Camera (0bda:5634)
[ 5008.996702] input: Laptop Camera: Laptop Camera as /devices/pci0000:00/0000:00:14.0/usb3/3-7/3-7:1.0/input/input58
[ 5019.035975] usb 3-7: Product: Laptop Camera
[ 5019.038803] usb 3-7: Found UVC 1.00 device Laptop Camera (0bda:5634)
[ 5019.044546] input: Laptop Camera: Laptop Camera as /devices/pci0000:00/0000:00:14.0/usb3/3-7/3-7:1.0/input/input59
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I saw the mention of the switches and that they are optical somewhere, but can’t remember to quote the source.

As far as I can tell each switch is a U channel with a light emitter on one side, and a detector on the other. The part you move on the bezel just breaks the light beam. This creates a electronic on/off hardware switch.

Using an actual physical switch would tend to be a source of an intermittent connection over time. Hence the use of optical technology. Same thought process for the screen open switch being a Hall Effect sensor, which can work through a cover.

Fingernails are generally not opaque… So either you don’t have long enough fingernails (with opaque dark nail polish) or the sensor is seeing enough light through your nail :wink:

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According to the blog post the privacy switches cut the connection electrically: The 1080p Webcam

Both of these switches are optical switches where a vane will block the light from one side to a phototransistor on the other side. The photo transistor will then cut power to the camera circuit, or switch the mic data output from the mic to a dummy output that generates silence.

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I think the conclusion is that fingernails are not opaque to IR!

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I have a related question: is the camera indicator light also “hardwired” to the camera so that the light must turn on when the camera turns on and vice versa?

A longer and better explanation for what I’m asking about can be found here: https://www.youtube.com/watch?v=m0mMF7GaIR0

I’ve found it very frustrating that my Surface Go (original version) does not have this very basic feature, as the lights will independently turn on while the camera does not (especially annoying when I’m trying to sign in with Windows Hello), which shows the camera could turn on without the light.

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@Azure_Orchid Yep the camera indicator light is tied directly to the power supply for the sensor. So if the sensor is on, the LED will be on.

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the camera indicator light is tied directly to the power supply for the sensor

YOU GUYS ARE AWESOME!
FINALLY SOME PROPER HARDWARE WITH ACTUAL, ELECTRONIC SWITCHES, NO SOFTWARE BS!

You got yourself another customer :slight_smile:
I do hope all of your products are immensely successful and that the company grows proportionally. But … one last thing : please dont turn into Apple once you’re there. The world needs you guys like you are right now. It really does.

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Yesterday I was working on something using the Framework Laptop and Chrome started using my camera… Nothing I was directly using (that I remembered - in all fairness) required it.

So I flipped Chrome off with my middle finger and turned off both switches… And giggled like a little kid. This is finally a OFF I trust

Unlike with my MSI beast, where when I have camera and microphone turned “off” and still can hear my finger scraping across the microphone on the keyboard deck in my headphones. Certainly not “off”

.

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" ‘dark mode’ where it’ll off" everything that attracts attention… I own one of those for my work. It also locks as soon as I am 3 ft from it.

And Yep, my 2009 MSI has a wifi kill switch I use a lot.

I received a Batch 5 DIY on December 3, and it seems to work great with Ubuntu Studio 21.04. But I don’t see any indicator light for camera nor microphone. The tiny descriptive card that came with the computer also doesn’t seem to mention any such lights. I notice that in one switch orientation, there is a red stripe visible, but I’m not sure whether that means on or off.

With the dark bezel, the tiny size of the openings and switches, and my old guy eyes, I can barely see the switches and a couple of shiny squares, and farther outboard two tiny holes. I can easily be missing something.

I installed pinhole, and it appears that the light goes on only when software actually engages the camera. I think that the light was in the shiny square on the bezel. Also, it appears that the red stripe indicates that the camera or mic is off. I had guessed the opposite, since I took the red as a warning that the device might be engaged.

I don’t expect to use either device, so I mainly just need to know that I have them switched off. As long as the lights don’t fail, it appears that the lack of light can give me confidence that nobody is spying.

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This is correct. When the switches are red, it means that power has been cut to the camera and/or mic (depending on which switches you changed to red). When they’re black, it means that power is available to the camera and/or mic.

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I am very eager to experience this in person once my laptop arrives early this next week. In the reviews seen online this past summer by various tech YouTubers, I was curious how those switches worked. Glad I found this post.

OK So my machine was shipped with them on :frowning:

That’s the default…otherwise there would be complaints about them not working.

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With the orange bezel, the red color is really hard to discern, FYI. Consider adding a symbol for on/off on the appropriate side of each switch in future versions. Love the switches, btw.