Alternative (and incompatible) layout for USB connectors

• DISCLAIMER: I DO ELECTRONICS AND 3D DESIGN SOLELY AS A HOBBY. THERE COULD BE ERRORS THAT CAN RESULT IN ALL KINDS OF DAMAGE. USE THESE DESIGNS AT YOUR OWN RISK.
• This design is released under Creative Commons Zero (CC0) license.
• Authors:
  • Svjatoslav Agejenko
    • Homepage: https://svjatoslav.eu
    • Email: svjatoslav@svjatoslav.eu
  • Valeria Agejenko
• See also:
  • Other physical projects in this repository
  • Other projects hosted at svjatoslav.eu

Warning! Here I describe a hack that I personally found useful for my own needs. But it is dangerous. Not to be replicated unless you know that you are doing.

I needed a way to power various devices I build.

Requirements:

• Reliable.
• Cheap.
• Easy to use.
• Popular and highly available.
• Ability to draw significant current directly from 12V cheap, popular and powerful lead-acid battery (optionally off-grid). Useful for powerful electric motors, heaters, soldering irons, radio transmitters, etc.
• Ability to draw limited but stabilized 5V power. Good for digital circuits.
• Ability to have limited and simple 1-wire digital communication.

USB Type A connectors are best match that I found.

The main problem is, I like USB connectors but I want to use different and incompatible electrical layout with them.

Connecting proper USB power supplies, devices and even cables to the ones that use alternative electrical layout would do damage!!!

To avoid accidental mismatches, I mark all connectors/cables and devices that use alternative wiring with printed, laminated warning stickers.

Alternative wiring schematic:

• Outer shell is ground.
• 2 central pins are re-purposed to deliver +12V and high power.
• 1 pin is for limited power +5V.
• 1 pin for 1-Wire data.

Example warning marking on device to indicate that alternative USB layout is used here: