02-14-2024, 11:33 AM
After more debugging, I have more questions than I have answers.
The PINE64 Wiki says that the PinePhone powers the PPKB via the POGO pins, specifically via the USB-5V pin. But this pin doesn't seem to be connected to anything on the PPKB mainboard. I checked the schematics, it's supposed to enter the junction pad J2, but J2 has 6 input pins and only 4 wires connect to it (USB-5V isn't one). I also checked with the multimeter, it seems like there's no connection...
However, the MCU seems to work on the 3.3 V that's provided by the USB debugging connection (the one I soldered to the mainboard). When not connected to USB, I can't seem to figure out on the schematics where is the 3.3 V supposed to come from and be provided to the MCU.
But the MCU never wakes up unless powered via the USB debugging connection. This seems to be the core issue. Having the battery connected to the mainboard doesn't work. Having a USB-C cable provide power on its charging port also doesn't work.
I also cannot tell whether the TXS0104ED chip has any role in powering the MCU. I don't think it's supposed to.
I'm convinced someone more knowledgeable could easily decipher all these issues...
The PINE64 Wiki says that the PinePhone powers the PPKB via the POGO pins, specifically via the USB-5V pin. But this pin doesn't seem to be connected to anything on the PPKB mainboard. I checked the schematics, it's supposed to enter the junction pad J2, but J2 has 6 input pins and only 4 wires connect to it (USB-5V isn't one). I also checked with the multimeter, it seems like there's no connection...
However, the MCU seems to work on the 3.3 V that's provided by the USB debugging connection (the one I soldered to the mainboard). When not connected to USB, I can't seem to figure out on the schematics where is the 3.3 V supposed to come from and be provided to the MCU.
But the MCU never wakes up unless powered via the USB debugging connection. This seems to be the core issue. Having the battery connected to the mainboard doesn't work. Having a USB-C cable provide power on its charging port also doesn't work.
I also cannot tell whether the TXS0104ED chip has any role in powering the MCU. I don't think it's supposed to.
I'm convinced someone more knowledgeable could easily decipher all these issues...
