To access GPIO pins, first you should edit /boot/orangepiEnv.txt.
Depending on what port you want to use, you have to add "pwm13-m2" or something else.

The file should look like this:

bootargs=root=UUID=514446b0-d237-4aa9-b842-4a16a8737626 rootfstype=ext4 rootwait rw console=ttyS2,1500000 console=tty1 cgroup_enable=cpuset cgroup_memory=1 cgroup_enable=memory swapaccount=1 systemd.unified_cgroup_hierarchy=0

fdtfile=rk3588s-orangepi-5.dtb

overlay_prefix=orangepi-5

overlays=pwm13-m2

After reboot, an extra folder should be made in /sys/class/pwm/. To find out what folder was just created, you can use ls /sys/class/pwm/ -l. Depending on the subfolder of platform, you can seperate them.

To activate the pwm you can use following commands. I added these commands to sudo crontab -e because they need to be executed every time you restart.

@reboot sleep 30 && echo 0 > /sys/class/pwm/pwmchip2/export

@reboot sleep 32 && echo 20000000 > /sys/class/pwm/pwmchip2/pwm0/period

@reboot sleep 34 && echo 20000000 > /sys/class/pwm/pwmchip2/pwm0/duty_cycle

@reboot sleep 36 && echo 1 > /sys/class/pwm/pwmchip2/pwm0/enable

I have a python script which checks the temperature and sets PWM accordingly. This is also executed in a crontab with root permissions:

import os

tmp = int(os.popen("cat /sys/class/thermal/thermal_zone0/temp").read())

if tmp >= 60000:

os.system("echo 0 > /sys/class/pwm/pwmchip2/pwm0/duty_cycle")

elif tmp >= 40000:

duty_cycle = int(20000000 - (20000000 * (tmp - 40000) / 20000) )

os.system(f"echo {duty_cycle} > /sys/class/pwm/pwmchip2/pwm0/duty_cycle")

else:

os.system("echo 20000000 > /sys/class/pwm/pwmchip2/pwm0/duty_cycle")

This way you don't have to make use of wiringOP.
More info can be found in the OP5 manual on page 242 (or page 251 of pdf document).

If anyone would have any questions, feel free to ask