First of all we need to install WiringOP command gpio. For controlling Orange PI build in GPIO pins.

WiringOP installation you can find here - https://github.com/zhaolei/WiringOP#installation

Installing WiringOP:

$ git clone https://github.com/zhaolei/WiringOP.git -b h3

$ cd WiringOP

chmod +x ./build

sudo ./build

For me script is inside /root directory. And script file name is fan-controller.sh.

First step is creating script file:

$ sudo nano /root/fan-controller.sh - for creating script inside /root folder

Paste my fan-controller.sh code inside your new created file.

$ sudo chmod +x /root/fan-controller.sh - for adding exacutable status to file

Now add fan controller script to crontab.

$ sudo nano /etc/crontab - open crontab file

And now at the bottom of file add line: */2 * * * * root bash /root/fan-controller.sh

Now script will execute every 2 minutes and run our new created file /root/fan-controller.sh

Information about crontab - http://www.adminschoice.com/crontab-quick-reference

Information about gpio - https://github.com/zhaolei/WiringOP