On Thursday, February 26, 2015 at 5:18:51 PM UTC+2, [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. >
Hi, You need to enable the ADC either by enabling the correct "cape" with capemgr (only in kernel 3.8.*, see e.g. http://hipstercircuits.com/reading-analog-adc-values-on-beaglebone-black/), or by enabling it in the .dts-file (later kernels, such as the 3.18.4 which I'm using). Matti > > 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.
