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I have an embedded Raspberry Pi in an enclosure, with a micro-USB female socket (see middle picture) for power input.

Is it correct to power the Raspberry Pi like this (micro-USB socket VCC to GPIO 5V pin #2 and micro-USB socket GND to GPIO GND pin #6)?

Will there be some voltage regulation?

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Will it be exactly the same as if the charger is directly connected to the Raspberry Pi micro-USB female socket, like this:

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Would there be better voltage regulation/protection with this choice?

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  • The voltage regulation will depend on your wall-wart, which typically isn't all that good and doesn't matter much for charging purposes, where there isn't much need for stability (the battery won't have issues if the voltage drops/fluctuates)
    – user2813274
    Apr 5, 2015 at 16:51

2 Answers 2

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It is acceptable to power the Pi via the GPIO pins, however to comply with the guidelines you should implement a power isolation circuit (as in the B+ or Pi 2 schematic). Direct connection bypasses the overvoltage protection but is acceptable with a well regulated supply (which most mobile chargers aren't).

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  • What component should I add to do the protection?
    – Basj
    Apr 5, 2015 at 12:19
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    @Basj well, if your bypassing the polyfuse's protection and want to add protection, a polyfuse would be a place to start - or just go with a power source that has an equivalent protection built-in
    – user2813274
    Apr 5, 2015 at 16:52
  • See learn.adafruit.com/…. This is an extract from the B+ schematic the Pi2 is identical.
    – Milliways
    Apr 7, 2015 at 17:05
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There will be the normal voltage regulation, i.e. 5V will be unregulated but 3V3, 2V2, 1V8 will be regulated.

As far as I'm aware all you lose is the protection of the 1 or 2 amp polyfuse fitted at the microUSB (depending on Pi model).

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