01-14-2022, 09:13 AM
You can find the schematics for the PinePhone at least in the wiki (no PCB files though). Look for "SW1-[A-F]", those should be the kill switches.
It looks to me like:
- SW1-A cuts off the modem's power system
- SW1-B disables the WIFI/BT module (assuming that the chip is disabled if CHIP_EN is pulled down)
- SW1-C disables MICBIAS; I think the mic might still work in this case, but with barely audible volume. If that is really the case, it would be a security flaw in my opinion, but it should be tested before making assumptions. Maybe the mic doesn't work at all without the bias voltage.
- SW1-D and SW1-E cut power to the rear and front camera sensors respectively
- SW1-F connects to an analog switch which switches between headphone out R/L (open) and serial TX/RX (closed)
I'm guessing that the schematics for the PinePhone Pro will be made available too. Probably it will not be too different in regards to the kill switches.
It looks to me like:
- SW1-A cuts off the modem's power system
- SW1-B disables the WIFI/BT module (assuming that the chip is disabled if CHIP_EN is pulled down)
- SW1-C disables MICBIAS; I think the mic might still work in this case, but with barely audible volume. If that is really the case, it would be a security flaw in my opinion, but it should be tested before making assumptions. Maybe the mic doesn't work at all without the bias voltage.
- SW1-D and SW1-E cut power to the rear and front camera sensors respectively
- SW1-F connects to an analog switch which switches between headphone out R/L (open) and serial TX/RX (closed)
I'm guessing that the schematics for the PinePhone Pro will be made available too. Probably it will not be too different in regards to the kill switches.