I tried using the wiringPi GPIO library just to test some basic IO, but when I tried to output HIGH on a pin (GPIO 25) the voltage only went from 0V to 0.03V, is this normal?

If this is normal that's rather useless because I cannot bit bang anything at those levels, right?

  • BCM GPIO25 or pin 25? As pin 25 is the GND pin, so always 0volts. (Pin numbering is totally insane. Physical pin 22, is GPIO 6 on the pi, and GPIO 25 on the BroadCom chip.)
    – Gerben
    Nov 28, 2013 at 16:44
  • I am using GPIO 25 as in Broadcom numbering
    – Gerharddc
    Nov 28, 2013 at 16:50
  • So pin 22. That is definitely not normal. Output voltages should be 3.3V. Have you tried a different pins?
    – Gerben
    Nov 28, 2013 at 17:48
  • It seems all seems to work after a reboot
    – Gerharddc
    Nov 28, 2013 at 18:53
  • Glad you got it working.
    – Gerben
    Nov 28, 2013 at 19:18

1 Answer 1


Very strange but a reboot seemed to fix the issue, so if you also have it, try rebooting!

  • 3
    By the way, if you've resolved this issue, could you please mark this answer as such? That would be great :) Apr 1, 2014 at 14:03

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