A USB-A to USB-C cable is required because the QuickLogic thing+ USB Type C connector is not implemented correctly
Posted: Sat Oct 21, 2023 4:57 am
Hi, when debugging why a USB-C to USB-C cable wouldn't even get power on a MacBook Pro port, I stumbled across the schematics for the QuickLogic thing+
Unfortunately the USB-C implementation is 100% out of spec -- it doesn't connect the CC1/CC2 pins to anything (!) when it needs to connect them to ground via a 5.1k termination resistor.
https://github.com/sparkfun/QuickLogic_ ... ematic.pdf Take a look at the USB-C connector: the CC pins are simply left floating. Without them the host won't even know there's anything on the line and doesn't allow any power.
Unfortunately the USB-C implementation is 100% out of spec -- it doesn't connect the CC1/CC2 pins to anything (!) when it needs to connect them to ground via a 5.1k termination resistor.
https://github.com/sparkfun/QuickLogic_ ... ematic.pdf Take a look at the USB-C connector: the CC pins are simply left floating. Without them the host won't even know there's anything on the line and doesn't allow any power.