> > *So I went back to the basic, and just ran the code without plugging > anything in, and yet the voltage value I'm printing says 1.6 instead of 0. > Below shows the code, which I got from adafruit. I'm aware that I'm not > supposed to connect BBB ADC to anything above 1.8V or below 0V, which I > don't believe I have.* >
Ok, somehow I managed to miss this paragraph when I first posted. So Chelsea, if you have not enabled the internal pulldown for the ADC pin in question, where you're getting 1.6v. That makes perfect sense. These pins will return a value in the mid to high range values when left floating. Typically when I did experimentation I would read between 2500's and 4500's. *I've also been reading somewhere that I may have to enable the ADC before > I can read it??* > I really do not see how you can be getting any values out of the ADC at all if it's not already enabled. ut here is a short "primer" I wrote concerning the onchip ADC: http://www.embeddedhobbyist.com/2015/10/beaglebone-black-adc/ On Sat, Feb 13, 2016 at 1:36 AM, TJF <[email protected]> wrote: > Hi Chelsea Orefice! > > 1V6 at an open pin looks good. AIN7 is connected to 1V65 at the board > (half of power line) and that voltage pulls up the other pins, when open. > When connecting P9_40 to ADC_GND you should see a values close to zero. > > You could use the libpruio <http://beagleboard.org/project/libpruio/> > example oszi > <http://users.freebasic-portal.de/tjf/Projekte/libpruio/doc/html/_cha_examples.html#SubSecExaOszi> > to study the ADC behaviour. > > BR > > -- > 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. > -- 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.
