18

I'm a newbie to Raspberry Pi's, but one of the things I was thinking about doing is running it off batteries (I see many people do this) - that led me to concerns about shutting down gracefully. Is there a software only solution that would allow me to detect input voltage?

10

you'll need some external circuitry to do that, because afaik the raspberry does not provide the battery voltage anywhere in the system: http://raspi.tv/tag/raspberry-pi-monitoring-its-own-battery-voltage

  • Apparently this is not true anymore, since newer boards show an thunderbolt icon when underpowered. – Dmitry Grigoryev Jan 19 '17 at 11:46
11

Use vcgencmd will show the internal voltages for core, sdram_c, sdram_i, and sdram_p:

vcgencmd measure_volts core

The output will look something like this:

volt=1.20V

The following shell commands will display all the voltages:

for id in core sdram_c sdram_i sdram_p
do
    echo -e "$id:\t$(vcgencmd measure_volts $id)"
done
  • what should be the voltage for each? – HelpNeeder Dec 20 '16 at 4:56
  • 4
    Unfortunately these are all things inside the 3.3V regulator, meaning not so handy for detecting a gradual decline on the 5V rail. – goldilocks Jan 18 '17 at 19:22
0

No, but MoPi is a tidy little board that provides the capability.

  • 1
    Can you explain how to use MoPi? – Kachamenus Oct 14 '15 at 21:51

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