Spurious headphone detection interrupts
I've also tried to find an appropriate TRRS socket, but it seems that no appropriate types are available.  The part you found, SJ-435107RS, unfortunately probably wouldn't fit mechanically because it isn't an SMT component that sits inside a PCB cutout, as it is the case with the current TRRS socket on the daughterboard.  There is probably not enough space inside the laptop to use any other variant of the connector.

Another option for a better headphones detection mechanism would be to use the ES8316 audio codec, which can generate required interrupts upon (un)plugging the headphones.  Furthermore, related NC or 0R components in the PineBook Pro schematics indicate that the design initially used ES8316 to detect the headphones, following the reference design found in the ES8316 datasheet (page 4), but that part of the circuitry has been made inoperable for the production version.

Could the RS232-to-USB bridge you've decribed actually be an USB-to-UART bridge such as the "official" serial console cable, which basically converts a SoC's native UART into a virtual serial port over USB?  Could you, please, confirm that or provide some additional information, such as an example of the actual bridge chip or device?  What is required of the RS232 DTE in that case, or the DTE is actually the virtual serial port in the computer that is connected to the USB interface of the bridge?

If that's actually the aforementioned USB-to-UART bridge, I would rather not see it in the next PineBook Pro revision.  Why?  First, it would require a USB Type-B socket on the side of the laptop, as a Type-A socket may not be used for something that is effectively a USB device port.  Second, it would increase the price of the laptop, for something that not all end-users need, and especially not all the time; anyone in need of a console port should buy a $7 console cable as an accessory.  Third, it would increase the power consumption ever slightly for something that is pretty much never used 100% of the time.

Out of the three reasons from above, the need for a USB Type-B socket would present the biggest issue, IMHO.  Just think of the users confused by a weird-looking USB port found literally on no other laptop; who knows what people would try to plug into that Type-B port. Smile

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RE: Spurious headphone detection interrupts - by dsimic - 02-10-2021, 06:04 PM

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