By the way, don't worry about mmap(). It's an C/C++ API call meant interact directly with a systems memory. e.g. you can poke / prod any memory location for good, and even bad purposes. Usually using mmap() in this manner is frowned on, as it can be insecure, or can lead to system instability if one does not know what they're doing. Essentially, you bypass the kernel completely when doing this, and is one reason why it can be so fast.
On Tue, Mar 8, 2016 at 3:09 PM, William Hermans <[email protected]> wrote: > Well, one shot mode is good for close to 6k reads / second *if* one needs > / wants to. Well, realistically, because of CPU usage. I'd probably limit > oneshot mode to around 3-4k samples a second. Once a second is definitely > no problem. > > http://www.embeddedhobbyist.com/2015/10/beaglebone-black-adc/ > > The example code is C, but perhaps you can use it to write an interface > for C#. > > On Tue, Mar 8, 2016 at 1:38 PM, 'PatM001' via BeagleBoard < > [email protected]> wrote: > >> Wow, didn't mean to start a war! >> >> Libpruio looks great but as mentioned, no C# version. I'll have a look at >> that utility mentioned above for converting to other languages. >> >> I don't know anything about mmap, I'll have to google that. >> >> As it is the app I'm working on only needs to read the ADCs once per >> second and the low passes are working so well I just take the average of 10 >> samples in a row (something like 16ms for three ADC 10x each). Even once >> per second is overkill (the process change is quite slow - like 5-30 >> minutes from one extreme to the other). >> >> Anyway, faster sampling was so that I could make a rudimentary >> oscilloscope for playing around with low pass filter configurations. Just >> using the default BB-ADC overlay I get some 800+ samples per second (which >> I'm sure a lot are probably reading the same value multiple times) and it >> does give me all the info I need for tuning up the input filters. >> >> >> On Thursday, March 3, 2016 at 10:25:52 PM UTC-8, TJF wrote: >> >>> Hi John! >>> >>> Thanks for that link. Another issue first: >>> >>> We're poluting this thread by interesting, but off-topic stuff. I hope >>> you don't mind that I switch our discussion to the new thread and >>> answer there >>> <https://groups.google.com/forum/#!category-topic/beagleboard/ZTKntXOXGyc> >>> . >>> >>> 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.
