To answer a question asked: the generic_buffer.c works fine with 4.1.5-ti-r10. The only thing I found is that the scale is not implemented (it's 1.0) so where you should be getting a value in Volts, you still get the 12 bit value from ADC (0 - 4095). Otherwise it pretty much works out of the box.
On Thursday, 13 August 2015 06:51:22 UTC+8, Maro wrote: > > Hoping you guys can help me out on this: > > Goal: High sample rate of one ADC line via a kernel module and a > corresponding user space app > > Now I know the PRU would be great for this- and I plan on also writing a > pru version to bench mark the diff but I'm currently trying to get it done > with a kernel module and its turned into one of those annoying obsessions > that should work and damn it-- I am going to make it work > > So the goal is almost identical to the generic_buffer.c application > referenced on this wiki [ > http://processors.wiki.ti.com/index.php/AM335x_ADC_Driver's_Guide] > > but I've been fight it for awhile with no results. > > Current version: Linux beaglebone 3.8.13-bone70 > 1: pulled there git repo > 2: applied the patch to get rid of the trigger stuff found here > 3: compiled: > gcc --static generic_buffer.c -o generic_buffer > 4: Issues happen now because sysfs seem to be so different, I'm not sure > contionous mode can be turned on? > > ./generic_buffer -n tiadc -l 256 -c 1 > iio device number being used is 0 > Problem reading scan element information > diag /sys/bus/iio/devices/iio:device0 > > > 5: This error leads down the rabbit hole to this semi unhelpful blog post: > https://e2e.ti.com/support/arm/sitara_arm/f/791/t/365886 yielding an > errata about `Continuous capture mode is not supported in the 3.12 kernel`; > great we are still rocking a 3.8.13 kernel thus should be fine? > > -------------------------- > Couple questions: > 1: Is there bbb kernel version that plays nice with the iio driver that > will allow this generic_buffer.c to work? if so details please > 2: if not has anyone modified this demo app to make things work? I've seen > a couple posts about it here > 2: Is there any information to say screw it and read the adc values > directly in my own ko? I've seen instructions on gpio but not the adc > lines. > -- 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 beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
