Advantech EPC-R4680, User Manual

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21 EPC-R4680 User Manual
Chapter 3
S
oftware
Functionality
Used as IRQ signal
Note: You have to configure GPIO to input
Unexport GPIO0
GPIO 219 and GPIO 220 are taken as an example:
Connect GPIO 219 and GPIO 220
Export GPIO 219 and GPIO 220
Set GPIO 219 to output
Set GPIO 220 to input
Change GPIO 219 to 1 and read GPIO 220 value
Change GPIO 219 to 0 and read GPIO 220 value
shell@rsb4680:/ $ echo "rising" > /sys/class/gpio/gpio219/edge
NOTE: rising: Trigger on rising edge
falling: Trigger on falling edge
both: Trigger on both edges
none: Disable interrupt on both edges
shell@rsb4680:/ $ echo 219 > /sys/class/gpio/unexport
shell@rsb4680:/ $ echo 219 > /sys/class/gpio/export
shell@rsb4680:/ $ echo 220 > /sys/class/gpio/export
shell@rsb4680:/ $ echo "out" > /sys/class/gpio/gpio219/direction
shell@rsb4680:/ $ echo "in" > /sys/class/gpio/gpio220/direction
shell@rsb4680:/ $ echo 1 > /sys/class/gpio/gpio219/value
shell@rsb4680:/ $ cat /sys/class/gpio/gpio220/value
1
shell@rsb4680:/ $ echo 0 > /sys/class/gpio/gpio219/value
shell@rsb4680:/ $ cat /sys/class/gpio/gpio220/value
0