Daily Archives: 2025-04-17

Article note: It has been hard to find these gadgets, but it's an obvious fix for all the extremely shittily implemented things that use a USB-C connector to accept 5V power input without the required sense resistors.

Do you have any devices with USB C connections that don’t seem to power or work when plugged into another USB C port? Chances are, the designers skimped a few pennies or just forgot to put in the two 5.1K CC resistors required for C-to-C connections at 5V. It can drive you batty because some computers care and some don’t!

That’s why we designed the Adafruit USB Type C CC Resistor Fixer, a collab between our  sunken USB socket and USB Plug breakout. It’s the only product we hope we can discontinue one day, sooner rather than later! This small PCB assembly fits onto a cable or into the mis-designed port. It passes through the two data pins and the Vbus and Ground power lines, while adding the missing 5.1K resistors on the port side and a power good LED.

Note that the USB plug pinout doesn’t carry the sideband wires or the high speed pins, so this is good for USB charge/sync but not for high speed or specialty protocols. If you’re not sure, then it’s very unlikely you need them: those products aren’t going to mess up the CC resistors.

Article note: This is going to be interesting.

Article note: I got an Armatron at a yard sale as a kid, they are delightful toys that are really good at making you think about task complexity/dof/etc.