QuickLogic Thing+ has a broken USB-C implementation and requires a USB-A to USB-C cable to function

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Hi, when debugging why a connecting via 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 Plus.

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 both to ground via individual 5.1k termination resistors. This is a normative requirement of the USB spec: you can’t avoid this.

Take a look at the USB-C connector in the schematic: the CC pins are simply left floating. Without them the host won’t even know there’s anything on the line and doesn’t know to power it.

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Yep, that’s a problem.

A USB A to USB C cable might work if the A end is not USB 3. You’d need an adapter that fools the computer into believing your connecting a USB 1 or 2 device though.