> > *Typically when I did experimentation I would read between 2500's and > 4500's*. >
typo . . should be 3500's and that is out of 4095 possible as max value for the onchip ADC. On Sun, Feb 14, 2016 at 1:24 PM, William Hermans <[email protected]> wrote: > *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.
