5

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?

Enter image description here

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

Enter image description here

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

  • 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 '15 at 16:51
7

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).

| improve this answer | |
  • What component should I add to do the protection? – Basj Apr 5 '15 at 12:19
  • 1
    @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 '15 at 16:52
  • See learn.adafruit.com/…. This is an extract from the B+ schematic the Pi2 is identical. – Milliways Apr 7 '15 at 17:05
4

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).

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.