| ▲ | MaxikCZ 16 hours ago |
| A capacitor can hold enough charge to power led for noticable amount of time even if powered for a brief moment, no logic needed |
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| ▲ | squarefoot 15 hours ago | parent | next [-] |
| I don't think they would waste a high value capacitor just to keep a led lit for longer, also a led directly lit by a capacitor would be noticeable by slowly dimming when the capacitor discharges. It's more likely that the signal driving the led comes out of a monostable implemented in code: pin_on() drives the led on; pin_off() waits n secs then drives the led off. |
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| ▲ | altairprime 11 hours ago | parent | next [-] | | This is Apple, so that assertion isn’t guaranteed valid like it would be for non-enterprise HP or Lenovo. They absolutely would invest in a capacitor if that’s what it takes, as they are maximally focused on camera privacy concerns and have made a point of that in their security marketing over time; or else they wouldn’t be allowing hardware security engineers to brag about it, much less talk publicly about it, at all. EDIT: It’s not just a capacitor, it’s a full custom chip, that can’t be software-modified, that keeps the light on for 3 seconds. https://news.ycombinator.com/item?id=42260379 | |
| ▲ | 12 hours ago | parent | prev [-] | | [deleted] |
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| ▲ | HeyLaughingBoy 10 hours ago | parent | prev | next [-] |
| Logic on an already existing ASIC is going to be cheaper than a capacitor. |
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| ▲ | MrDrMcCoy 6 hours ago | parent [-] | | This is counter-intuitive enough to warrant further explanation. | | |
| ▲ | ale42 3 hours ago | parent [-] | | If you are designing an ASIC for the camera, you can include all the required logic gates to control the LED for a cost that is close to zero. It wouldn't impact the production cost of the ASIC, whereas a capacitor is an additional item in the BOM (and to be charged it requires current, more than the LED, so the driver in the IC must be bigger). |
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| ▲ | RA2lover 16 hours ago | parent | prev [-] |
| The trick is to keep using the camera until that capacitor is discharged. I'm pretty sure most cameras can run at voltages below a LED's forward voltage nowadays. |
