Charge-only USB cables

Here’s how to quickly determine if a USB cable is fully operational or charge-only.

1. Purchase several identical USB gadgets that require data transfer but are cheap and therefore don’t come with their own cables; e.g. a fun microcontroller like an ESP8266.
2. Grab a cable from your big box ‘o cables that you can’t bring yourself to throw out
3. Test it, doesn’t work - powers on, but not identified on computer.
4. Test with two other cables, just to be sure it’s not the cable.
5. Test all of the gadgets you got - same problem across the board.
6. Suspect your computer; try another one. Try another OS or two.
7. Read up about debugging the device and whether this is a known fault; identify online posts about several similar-sounding but ultimately unrelated issues.
8. Begin to package gadgets for return/trash, nearly admitting defeat
9. In a moment of desperation, try hooking up another micro-USB gadget to your computer. Discover that doesn’t work either.
10. Question own sanity.
11. Try three other cables from your big box ‘o cables. One finally works with the other gadget.
12. Try that cable with the little microcontroller. Still doesn’t work.
13. Discover this is actually yet another cable, which looks identical to the one that does work.
14. Become very angry.
15. Get some brightly-colored electrical tape in two colors.
16. Use the electrical tape to mark each and every last damned cable in the damned box, with the two colors denoting “worked at least once” and “POS cable for charging ancient crap only”
17. You can now easily identify the fully-operational USB cables, as they will have a brightly-colored electrical tape indicating this!

(if any additional unmarked micro-USB cables should appear, go back to step 14)