GPIO keys
From ArmadeusWiki
How to use gpio-keys driver to read states of the user switch of your Armadeus board (APF51)
Introduction
Your APF51 board features a user switch connected to a GPIO pin (GPIO1_3). The driver gpio-keys translates GPIO events in key/button events.
Test
# cat /dev/input/event0
Then you should see weirds characters when pressing the user button of the apf51_dev board:
T ����T �T � ��T %�
- if the test wiped out your console, you can get it back with:
# reset