zlacker

I assume you're not longer working on it, but why not just wire it so that:

- The LED is in parallel, but with the sensor voltage supply, not the chip

- Camera sensor idle voltage = low voltage for the LED (be it with stepping if needed)

- Camera sensor active voltage = high voltage for the LED (again, stepping if needed)

- little capacitor that holds enough charge to run the LED for ~3 seconds after camera goes back to idle voltage.

Good luck hacking that :)

>>jorvi+(OP)
That's basically how this works, but manufacturing electronics at a massive scale requires some more flexibility. For example, capacitors have a pretty large tolerance (sometimes +/- 20%) and LEDs have quite a bit of variety in what voltages they'll work at. So for some people the LEDs might last 3 seconds, for some they might last 5s. Using a capacitor also means the LEDs will fade slowly instead of just turning off sharply.

If the LEDs come from a different supplier one day, who is going to make sure they're still within the spec for staying on for 3 seconds?

(And yes, I have long since parted ways with Apple)

Edit:

And to add on: That capacitor needs time to charge so now the LED doesn't actually come on when the sensor comes on, it's slightly delayed!

>>jorvi+(OP)
You can't drive an LED that way in production electronics: you need to use an LED driver circuit of some kind to ensure the LED has constant current, and also to protect against failure modes. Also, a capacitor large enough to power a daylight-visible LED for 3 seconds is not as "little" as you're thinking; there's likely not enough space in a laptop lid for one of those. A driver circuit would be smaller and thinner.

Agreed, however, that the LED should be controlled by the camera sensor idle vs. active voltage.

>>axoltl+wa
Thank you for the clarifications. Armchair (well, workbench) engineering strikes again haha!