Additional problem on Raspberry Pi (model 3): there is no:
/sys/class/gpio
This does exist with the 4.8.15-300 kernel, but it has problems:
[root@RPi3-1 gpiochip970]# echo 993 >/sys/class/gpio/export
[root@RPi3-1 gpiochip970]# echo 1 > /sys/class/gpio/gpio993/value
bash: echo: write error:
4.9.2 does not appear to do much good. The blank screen problem
https://bugzilla.redhat.com/show_bug.cgi?id=1387733
continues, and the
kernel: i2c-bcm2835 3f805000.i2c: i2c transfer timed out
message still appears in the journal.
The following document my experience:
