A DIY Google Twinkie Sniffer
As many people have discovered, not all USB-C cords are the same. Your device might be capable of delivering 90W of power but the cord you plug in might not handle anything near that. This generally just results in poor charging behaviour, which is annoying enough as it is, but has previously lead to fires when a cord is asked to handle far more wattage than it is capable of.
There are USB-C power delivery sniffers you can buy on the market, but they are not inexpensive and are limited in their functionality. This project over at Hackaday describes how you can build your own sniffer from relatively inexpensive parts. As the entire design is open source, an enterprising maker could add functionality to it, to be able to test issues with data transfer, video passthrough or even redesign it to test Thunderbolt cables. The full project files can be found there if you are interested in building one for yourself.
