6 ms·

My suspicion is there's a hardware method of detecting lid closed - probably detecting a physical magnet (which is used anyway so that lid closes nicely) and th

My suspicion is there's a hardware method of detecting lid closed - probably detecting a physical magnet (which is used anyway so that lid closes nicely) and that drives a transistor which then does the gating. I don't see why you assert that is has to be electro-magnetic based, as long as the gating is down by a 'dumb' fixed transistor rather than a programmable chip, then it's a hardware disconnect.

est31 7y ago
Interesting, it's magnet based. I've learned something today!
lukifer 7y ago
In the same spirit as putting tape over the webcam, I'd love it if someone found a solution for putting a tiny magnet in exactly the right spot to force-disable the microphone while the lid is open. :) I hope you're right, and I'd agree that would qualify as a "hardware disconnect". It's a little confusing given the mention of the T2 chip; they do differentiate some specific models which are "hardware alone", and at least imply that the T2 chip does not flip the off-switch on those. I'll have to go dig into iFixit's tear-downs to see if they found anything. For the 2020 iPad, they specifically mention "MFI compliant cases", so we can be fairly certain that one's done with magnets.
- duskwuff 7y ago
  > I'd love it if someone found a solution for putting a tiny magnet in exactly the right spot to force-disable the microphone while the lid is open. :) It's the same sensor that's used to detect if the lid is open in general. Triggering it will prevent the display from turning on, and will make the computer go to sleep if it isn't running in "clamshell mode" (running on AC power with an external display attached).
  - lukifer 7y ago
    Disappointing, but makes sense, thanks for sharing.
- benhurmarcel 7y ago
  > For the 2020 iPad, they specifically mention "MFI compliant cases", so we can be fairly certain that one's done with magnets. Why is that? Any case, including not "MFI", could put a magnet at the location if that was the case. Doesn't "MFI" mean that they make it only work with cases that are identified via the software to have paid their certification to Apple?
  - lukifer 7y ago
    That's a good question, I honestly don't know. My guess would be that MFI is essentially a checklist of all supported magnetic functionality, and therefore the experience Apple can promise in its marketing (ie, in addition to collecting fees, they don't want a user to blame Apple when a non-approved case doesn't work). I'd wager that a non-MFI case with magnets in the right places would still work; I don't think constraining to pre-approved RFID codes or anything like that.
diebeforei485 7y ago
iPad Pro has multiple mics on different sides of the device, so they'd need to have multiple of this.

est31 7y ago

Interesting, it's magnet based. I've learned something today!

lukifer 7y ago

In the same spirit as putting tape over the webcam, I'd love it if someone found a solution for putting a tiny magnet in exactly the right spot to force-disable the microphone while the lid is open. :) I hope you're right, and I'd agree that would qualify as a "hardware disconnect". It's a little confusing given the mention of the T2 chip; they do differentiate some specific models which are "hardware alone", and at least imply that the T2 chip does not flip the off-switch on those. I'll have to go dig into iFixit's tear-downs to see if they found anything. For the 2020 iPad, they specifically mention "MFI compliant cases", so we can be fairly certain that one's done with magnets.

duskwuff 7y ago
> I'd love it if someone found a solution for putting a tiny magnet in exactly the right spot to force-disable the microphone while the lid is open. :) It's the same sensor that's used to detect if the lid is open in general. Triggering it will prevent the display from turning on, and will make the computer go to sleep if it isn't running in "clamshell mode" (running on AC power with an external display attached).
- lukifer 7y ago
  Disappointing, but makes sense, thanks for sharing.
benhurmarcel 7y ago
> For the 2020 iPad, they specifically mention "MFI compliant cases", so we can be fairly certain that one's done with magnets. Why is that? Any case, including not "MFI", could put a magnet at the location if that was the case. Doesn't "MFI" mean that they make it only work with cases that are identified via the software to have paid their certification to Apple?
- lukifer 7y ago
  That's a good question, I honestly don't know. My guess would be that MFI is essentially a checklist of all supported magnetic functionality, and therefore the experience Apple can promise in its marketing (ie, in addition to collecting fees, they don't want a user to blame Apple when a non-approved case doesn't work). I'd wager that a non-MFI case with magnets in the right places would still work; I don't think constraining to pre-approved RFID codes or anything like that.

diebeforei485 7y ago

iPad Pro has multiple mics on different sides of the device, so they'd need to have multiple of this.