how to controll GPIO

#switch to rootsudo su -
#set GPIO to high
echo 1 > /sys/class/gpio/gpio339/vlaue
#set GPIO to low
echo 0 > /sys/class/gpio/gpio339/vlaue

I tried this command but it showed  Permission denied.How can I controll GPIO?

I was able to control GPIOs by adding users to a privileged group.
On the other hand, setting the output of the DO to high does not allow current to flow. I would appreciate your solution.

there is no GPIO 339, 339 is just a sample, please follow the instruction

GPIO Please change the code in <> to your GPIO export value #switch to root sudo su - #set GPIO to high echo 1 > /sys/class/gpio//vlaue #set GPIO to low echo 0 > /sys/class/gpio//vlaue For auto config, write above commands to file /etc/rc.local. UART Open device node in /dev/. Then use stty command to set parameters. See stty command manual for details, please change the code in <> to your UART device node. #config UART $ sudo stty -F /dev/ speed 115200 cs8 -parenb -cstopb -echo #send data...