sama5d3 环境检测　gpio--yx测试

说明:

ｇｐｉｏ的ＭＡＰ关系　yx0--20  yx1--16   yx2--12   yx3--10   yx4--14  yx5--4  yx6--2  yx7--0

使用ｃａｔ方式捕获电平，如果是字符‘1‘,代表输入节点没有闭合，如果是字符‘０‘,代表外部输入节点闭合，

1 配置gpio

[email protected]:~ echo 16  > /sys/class/gpio/export
[email protected]:~ echo 12  > /sys/class/gpio/export
[email protected]:~ echo 10  > /sys/class/gpio/export
[email protected]:~ echo 14  > /sys/class/gpio/export
[email protected]:~ echo 4  > /sys/class/gpio/export
[email protected]:~ echo 2  > /sys/class/gpio/export
[email protected]:~ echo 0  > /sys/class/gpio/export

2 配置gpio的方向－－输入

[email protected]: echo in > /sys/class/gpio/pioA20/direction
[email protected]: echo in > /sys/class/gpio/pioA16/direction
[email protected]: echo in > /sys/class/gpio/pioA12/direction
[email protected]: echo in > /sys/class/gpio/pioA10/direction
[email protected]: echo in > /sys/class/gpio/pioA14/direction                   
[email protected]: echo in > /sys/class/gpio/pioA4/direction                    
[email protected]: echo in > /sys/class/gpio/pioA2/direction                    
[email protected]: echo in > /sys/class/gpio/pioA0/direction

3 捕获电平:

[email protected]: cat /sys/class/gpio/pioA20/value //如果返回字符‘1‘,代表输入节点没有闭合，如果是字符‘０‘,代表外部输入节点闭合

[email protected]: cat /sys/class/gpio/pioA16/value

[email protected]: cat /sys/class/gpio/pioA12/value

[email protected]: cat /sys/class/gpio/pioA10/value

[email protected]: cat /sys/class/gpio/pioA4/value

[email protected]: cat /sys/class/gpio/pioA2/value

[email protected]: cat /sys/class/gpio/pioA0/value