My raspberry Pi GPIO are suddenly oscillating. Are there software/hardware tests that can be done to do a status check of the Pi hardware

I am looking for debugging

  • GPIO Status
  • Hardware Faults (like Polyfuse blown, Pull up resistors not working)
  • Other issues with the Pi that could be creating such issues

  • PS : I am aware of wiringPi and the readall function
  • 1. Why do you think "GPIO are suddenly oscillating"? 2. What is connected to the Pi? A software tool would be about No. 10 on my debug list.
    – Milliways
    Nov 4, 2016 at 11:46
  • My gut reaction would be that you're likely trying to read floating inputs, which would produce semi-random results.
    – goobering
    Nov 4, 2016 at 14:51
  • So, I was controlling some solenoids via a ULN2803 and the pi worked fine for several days. One day, the pi gpio started oscillating (I could see this as the solenoids would randomly rise and fall). I am taking input, but those GPIOs aren't affected. These are the output ones. What other tests can I do @Milliways? Thank you !
    – Aman
    Nov 6, 2016 at 20:45

1 Answer 1


To check the states try my piscope.

It may well help you track down the source.

A typical source of interference is a long unshielded wire connected to a GPIO acting as an aerial.

  • Will this work if the GPIO is spoilt? What are the reasons that could fry the GPIO?
    – Aman
    Nov 4, 2016 at 10:59
  • To check for broken GPIO use this test. GPIO which are fried don't normally oscillate, they generally are stuck high or low.
    – joan
    Nov 4, 2016 at 11:02

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