Sounds like you have a grounding issue with your scope. Make sure the power and scope are connected to the same power outlet that the scope probe ground is connected to the board ground.
Gerald On Tue, Dec 9, 2014 at 11:39 AM, Maxi Miller <[email protected]> wrote: > Hi, > I am running two BBBs via power adapter, and I wanted to test the GPIO > pins. One of them runs still on the manufacturing OS, the other one is > up-to-date. Now I wanted to see the GPIO pin values with an oscilloscope. > While trying to switch the pins on and off on the up-to-date-board via echo > on/off > <pin> I experienced that the pin I wanted to switch never changed > state. Therefore I tried to do the same on the other board, thinking that > it was a software fault. But there I only measured a 50Hz-triangular > signal, regardless which pin I chose (Even on GND and 5V). Why? What can I > do to bring both of them back to work? > Thanks! > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- Gerald [email protected] http://beagleboard.org/ http://circuitco.com/support/ -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
