ASUS TinkerBoard Setup

I/O File Permissions

File /etc/udev/rules.d/70-gpio.rules:

# Allow group gpio to access gpiomem device
SUBSYSTEM=="rk3288-gpiomem", GROUP="gpio", MODE="0660"

# Allow group gpio to access gpiochip files
SUBSYSTEM=="gpio", GROUP="gpio", MODE="0660"

# To allow additional features like edge detection
SUBSYSTEM=="gpio*", PROGRAM="/bin/sh -c '\
  chown -R root:gpio /sys/class/gpio && chmod -R 770 /sys/class/gpio;\
  chown -R root:gpio /sys/devices/virtual/gpio && chmod -R 770 /sys/devices/virtual/gpio;\
  chown -R root:gpio /sys$devpath && chmod -R 770 /sys$devpath\
'"