GPIO Btn read from Linux userspacce application

Snaidy1 · 01-17-2017, 05:01 AM

Hi Guyz,
I want to read the gpio status from my Linux application (user space) where an push button is connected.I want to know what are the method (Interrupt/ polling/ file read) I can make use to do it.

how I can get the interrupter from Linux GPIO driver to userspace ? is there a way ?

which is the best method to recognize & handle GPIO btn press in linux

Thanks,
Snaidy

eSelix · 01-25-2017, 03:58 AM

In user space you can use sysfs interface, for example in shell:

Code:

# for using gpio no. 5
echo 5 > /sys/class/gpio/export
echo "in" > /sys/class/gpio/gpio5/direction
cat /sys/class/gpio/gpio5/value
# and when you end
echo 5 > /sys/class/gpio/unexport

Most embedded devices uses device tree to describe its hardware, then you can use kernel modules for handling buttons: gpio-keys-polled or gpio-keys. More info at GPIO kernel documentation