#+TITLE: Alternative (and incompatible) layout for USB connectors
#+author: Svjatoslav Agejenko
#+LANGUAGE: en

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* General
+ 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: [[mailto://svjatoslav@svjatoslav.eu][svjatoslav@svjatoslav.eu]]

  - Valeria Agejenko

+ See also:
  - [[../../index.html][Other physical projects in this repository]]
  - [[https://www.svjatoslav.eu/projects/][Other projects hosted at svjatoslav.eu]]

* Project description

*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.


[[file:make.png]]

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 [[file:stickers.png][printed, laminated warning stickers]].

Alternative wiring schematic:
[[file:schematic.png]]

- 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:

[[file:../lab%20heater%20and%20cooler/make,%202.png]]