Tool to Control Fan - fanctl

[tuxd3v]

Just after I posted the reply with gcc version , I tried to build again and it worked, status active ! 
Now I will try to get the temp a bit up to see if the fan is starting.
I want to mention that I don't have a fan on rockpro64 directly(only a heatsink) , It's the NAS case fan that I try to make it work, but I guess your program is good for that too right?

Thank you !!

You have a older gcc version, the 6.3, the problem was what I expected  
I advise you to upgrade to 7.3 version( it has better support for ARM processors ):

If you want to maintain gcc-6.3 for some reason, you can use 'alternatives'.
First check if gcc is already registered in alternatives, if not, you can always do:

Code:

update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-6.3 50 --slave /usr/bin/g++ g++ /usr/bin/g++-6.3
update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-7.3 100  --slave /usr/bin/g++ g++ /usr/bin/g++-7.3

In this way gcc.7.3 will have a highest priority( 100 ) than gcc-6.3( 50 )

to remove a option, lets say gcc-7.3:

Code:

update-alternatives --remove gcc /usr/bin/gcc-7.3

to change order, just:

Code:

update-alternatives --config gcc

You may need to adapt timers, to better fit your fan specs..
Also you need to look, into current consumption, of the fan, the transistor that drives the pwm for the Fan, has a absolute maximum continuous current of 500 miliAmps.

But this is a maximum, we should operate bellow.

Usually fans conected there, are around 100 miliAmps,
What is the power and current of the Fan you have?