Hi, On Monday, March 2, 2015 at 8:04:40 PM UTC+2, Dajiang He wrote: > > Hi > > following ur guide, it almost worked. > > However, when issuing command > > echo 1 > /sys/bus/iio/devices/iio\:device0/buffer/enable >> > System gives me error: echo: wrrite error: Invalid argument > I already use root to issue to command, and strangely "echo 1 > > /sys/bus/iio/devices/iio\:device0/buffer/length" worked. > > Does your kernel present /sys/bus/iio/devices/iio\:device0/mode ? If it does, try issuing "echo continuous > /sys/bus/iio/devices/iio\:device0/mode" and then try to enable buffer again.
Matti > > On Friday, February 27, 2015 at 12:12:58 AM UTC+8, cmbaker3 wrote: >> >> What cape did you load? >> When I reboot, I see as you did >> >: ls -als /sys/bus/iio/devices/ >> total 0 >> 0 drwxr-xr-x 2 root root 0 Dec 31 1999 . >> 0 drwxr-xr-x 4 root root 0 Dec 31 1999 .. >> 0 lrwxrwxrwx 1 root root 0 Dec 31 1999 iio_sysfs_trigger -> >> ../../../devices/iio_sysfs_trigger >> >> After I >> echo cape-bone-iio > /sys/devices/bone_capemgr.9/slots >> then I see >> >: ls -als /sys/bus/iio/devices/ >> total 0 >> 0 drwxr-xr-x 2 root root 0 Dec 31 1999 . >> 0 drwxr-xr-x 4 root root 0 Dec 31 1999 .. >> 0 lrwxrwxrwx 1 root root 0 Feb 26 10:07 iio:device0 -> >> ../../../devices/ocp.3/44e0d000.tscadc/tiadc/iio:device0 >> 0 lrwxrwxrwx 1 root root 0 Dec 31 1999 iio_sysfs_trigger -> >> ../../../devices/iio_sysfs_trigger >> >> and >> >: cat /sys/devices/bone_capemgr.9/slots >> 0: 54:PF--- >> 1: 55:PF--- >> 2: 56:PF--- >> 3: 57:PF--- >> 4: ff:P-O-L Bone-LT-eMMC-2G,00A0,Texas Instrument,BB-BONE-EMMC-2G >> 5: ff:P-O-- Bone-Black-HDMI,00A0,Texas Instrument,BB-BONELT-HDMI >> 6: ff:P-O-- Bone-Black-HDMIN,00A0,Texas Instrument,BB-BONELT-HDMIN >> 7: ff:P-O-L Override Board Name,00A0,Override Manuf,cape-bone-iio >> >> Chad >> >> >> On 2/26/2015 4:03 AM, [email protected] wrote: >> >> Hi, >> >> How come in my system, there is no /sys/bus/iio/devices/iio:device0? >> Under /sys/bus/iio/devices/, there is only one file iio_sysfs_trigger, >> which is a symbolic link to some other directory. >> Is there any configuration I need to do? >> I am using the latest BB black Rev C by Element14. It is OS is >> 3.8.13-bone47. >> >> Thx. >> >> On Wednesday, February 25, 2015 at 8:36:18 PM UTC+8, [email protected] >> wrote: >>> >>> Thanks for the suggestion. I'll keep that in mind if I need higher >>> sampling rates. However, I did find a way to read ADC through IIO so that >>> it doesn't hang. >>> >>> First set up the channels and the buffer through sysfs: >>> >>> echo 1 > /sys/bus/iio/devices/iio\:device0/scan_elements/in_voltage0_en >>> echo 256 > /sys/bus/iio/devices/iio\:device0/buffer/length >>> echo 1 > /sys/bus/iio/devices/iio\:device0/buffer/enable >>> >>> and then read from /dev/iio:device0. This way I can achieve about 8 kHz >>> sampling rate with a single channel, 4 kHz with two channels and down to >>> ~300 Hz with all eight channels. >>> >> -- >> 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.
