What is it?

The C2C caberQU board applies a voltage to all pins of a cable and measures which ones are connected to the other end. It features LEDs for each of the 24 pins and even shield. So in total 25 LEDs offer all possible combinations for USB-C receptacle pin usage in different modes:

USB 2.0/1.1
USB Power Delivery
USB 3.0/3.1/3.2
Alternate Mode
Debug Accessory Mode
Audio Adapter Accessory Mode

Why did you make it?

The amount of possible USB C cable combinations is endless. If you use the wrong cable, data transmission may be slower than possible or certain devices may not work at all. In the USB C standard, the cable plays an important role and has to advertise itself as such. All of them need to have certain pins connected, some need to be grounded, some need to have resistors attached.
What makes it special?

Unfortunately there is no easy way to extract whether a certain cable can support a certain use case. If a cable has a broken pin, that makes it even worse, due to their unpredictable behavior. The C2C caberQU cable tester solves this once and for all. By flipping the USB connectors, the opposing LEDs for some pins light up due to them not being mirrored. That’s on purpose and defined in the USB C standard. The product is sold with one CR2032, the PCB and some basic instructions. The USB C cable is not included. You have to extract the needed pins for your desired usage on your own, unfortunately that can not be done universally for all possible combinations.

Electrical engineer Álvaro Prieto has called time on faulty or mislabeled USB cables, building a dedicated testing board with a wide array of USB connector types — and releasing it as open hardware to help others sort out their junk drawers too.

“Ever wonder if your USB [Type-]C cable is USB2 or USB3? Do you have some charge-only cables hiding in a box just waiting for the right moment to spoil your project plans?! Fear no more,” Prieto writes of the project. “I’ve made a simple board to test most of the things!”

https://github.com/alvarop/usb_c_cable_tester/blob/main/ORDERING.md

There’s no shame in admitting you’ve been burned by a cheapo USB cable — ever since some bean counter realized there was a few cents to be saved by producing “power only” USB cables, no hardware hacker has been safe. But with this simple tester from [Álvaro Prieto] in your arsenal, you’ll never be fooled again.

https://github.com/alvarop/usb_c_cable_tester

Designed for USB 2.0 cables with a range of connectors, this CR2032-powered tester offers quick and easy continuity checking.