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Mike Dorsett avatar image
Mike Dorsett asked

Raspberry Pi Zero USB Power

I'm wondering where the +5V power for the Pi Zero USB is derived from.

https://datasheets.raspberrypi.com/rpizero/raspberry-pi-zero-reduced-schematics.pdf

In the above link, the USB socket J10, has its power from "VBUS" which does not appear to be referenced elsewhere on the sheet. The power input socket J1 connects its power to +5V, so apparently does the 40 pin header (pins 2&4), J8.2, J8.4. However, if the Pi zero is powered by 5V input to pins 2 &4 on J8, there is no power on the USB socket.

Does any one have any more information on this? I did not have this problem with the Pi3... but I can't get more of these at the moment...

Raspberry Pi
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bradfordharley avatar image
bradfordharley answered ·

What is it that you are trying to do? Power the zero directly from the pins and use the USB for IO? Obviously, the zero is normally powered via the 5v over the USB port.


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Mike Dorsett avatar image
Mike Dorsett answered ·

Yes, I want to power the Pi directly from the pins on the expansion header, this works fine with 3 and 3+. The USB is for Ve direct inputs etc. The Pi is used like a daughter board on a BMS interface card that provides it with power.

One cannot find flying leads to provide power to the USB C, and it would look untidy too.

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taylortops avatar image
taylortops answered ·

RPI Pins 2 and 4 are one and the same with the +5V on the USB.

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Mike Dorsett avatar image Mike Dorsett commented ·
not on the one I have - about 6 years old, the usb remains unpowered when the device is powered off pins 2&4.
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