I'm trying to change the value of GPIO port manually.
To change the value of gpio18 (physical port 12), I did as follow:
# gpio unexportall
# echo 18 > /sys/class/gpio/export
# echo out > /sys/class/gpio/gpio18/direction
# cat /sys/class/gpio/gpio18/value #output is 0
# echo 1 > /sys/class/gpio/gpio18/value
# cat /sys/class/gpio/gpio18/value #output is 1
For gpio7 (physical port 26) I perform the exact commands as above. But the value remains 0:
# echo 7 > /sys/class/gpio/export
# echo out > /sys/class/gpio/gpio7/direction
# cat /sys/class/gpio/gpio7/value #output is 0
# echo 1 > /sys/class/gpio/gpio7/value
# cat /sys/class/gpio/gpio7/value #output is 0 again
I've tried with all other gpio ports. All ports function properly except gpio7 and gpio11 (the value is always 0).
By the way before using this raspberry pi, I was working with another raspberry pi2. Strangely the gpio7 in the previous raspberry pi had the same problem too. Is it a hardware problem or I am doing something wrong?
Edit: Only Ethernet cable and power bank are connected to raspberry pi. By the way this is the first time that I'm using this raspberry pi.