I have a USB type-C rapid charger 5V/3A, want to use that for one of my projects but there's 8 wires and i can't tell which is which to get 5V out of it!

sorry for the blurry image, couldn't get the camera to zoom properly.

there's 2 orange, 2 red, white, yellow, green and shield wire.

How can i can i get 5V from this wires? which is positive, which is negative?

  • 1
    \$\begingroup\$ The shield (braid) will be ground. Test the othes WRT to that to find the voltage you need. \$\endgroup\$
    – Majenko
    Jul 8 '19 at 15:38
  • \$\begingroup\$ Is the USB-A on the other side? I think you should do a continuity check from the physical wire to the pins on the USB-A side. \$\endgroup\$
    – user103380
    Jul 8 '19 at 15:39
  • \$\begingroup\$ @KingDuken it's a USB-C rapid charger from nexus 5X. \$\endgroup\$ Jul 8 '19 at 15:40
  • \$\begingroup\$ @newbie Understood. But what I'm saying is that it's USB-C on one side and USB-A on another, presumably. So you can probably run a continuity test using a multimeter if you have one. You just need to see the pinout for USB-A \$\endgroup\$
    – user103380
    Jul 8 '19 at 15:41
  • 1
    \$\begingroup\$ en.wikipedia.org/wiki/USB-C \$\endgroup\$
    – Majenko
    Jul 8 '19 at 15:44

It'll be the braided shield and the thickest red cable, but:

You'll be a bit disappointed in the current you'll be able to draw.

The USB-C specification allows for chargers to deliver high currents, but only to devices that speak the USB-PD profile. That's a complex protocol, and just cutting off the wires will not do it. See this answer that discusses what you'd need to do to convince a USB-C charger to deliver 20 V.

By the USB standard, your charger mustn't deliver more than a couple hundred milliamperes to a "dumb" device that doesn't negotiate a higher current; most chargers will deliver solidly more, but you won't be close to the maximum charging current, if you don't talk USB PD to the charger.

In older USB2 devices, Qualcomm QC is the most popular protocol to negotiate a high current draw; basically the same applies for QC as for USB PD.

  • \$\begingroup\$ I'm using it for Arduino and all i need is 5V and maximum 1A (500mA), is it gonna allow me to draw that without worrying about USB-PD chip? \$\endgroup\$ Jul 8 '19 at 15:55
  • 5
    \$\begingroup\$ again: spec-wise, the charger mustn't deliver 1A without you negotiating that, but it very likely will. It's a bit of luck. \$\endgroup\$ Jul 8 '19 at 15:57

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