How temperatures are changed

[Greifent]

Additional context
I was looking at the source code but since my understanding of bash is not good I couldn't figure it out: how are the temperatures set? And which system variable is used to read the temperature of the computer and select the correct fan speed?
This is for a thing that I would like to add on the GUI.
Thanks

[dominiksalvet]

Hello @Greifent! 👋

how are the temperatures set?

The lowest level of setting temperatures in asus-fan-control is write_acpi_temp() function. It sets a single temperature at a given address with a given value. This function is called by write_temps() several times.

The write_temps() function gets the base address and a list of temperature values. It sets the temperature at the base address with the first temperature of the list and continues with base address + 1 and the second temperature of the list. That repeats for all values of the list.

This is how the temperatures are actually set to ACPI/hardware. All wrapper functions just check temperature values, and their number based on model information stored in models file. If there is no record for a device (not tested ones), it will use defaults from UX430UA model.

Did you know you can enable execution tracing? E.g. for sudo asus-fan-control get-temps, you can use sudo sh -x /usr/local/bin/asus-fan-control get-temps and you will see every step the program does. How handy! 🚀

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And which system variable is used to read the temperature of the computer and select the correct fan speed?

Did I answer this above with the models file? If not, please clarify this question. BTW, there are functions with similar yet opposite effects as the ones above – read_acpi_temp() and read_temps().

[Greifent]

Thanks, that helped clarifying what the acpi do.
I meant: how the computer know the current temperature inside? Which sensor does it use? There is a way to know the temperature that the program use?

[dominiksalvet]

Ah I see. Asus-fan-control uses ACPI entry points \_SB.PCI0.LPCB.EC0.RRAM for read and \_SB.PCI0.LPCB.EC0.WRAM for write. Those entry points are used in the mentioned write_acpi_temp() and read_acpi_temp() functions. For more information, I suggest you to see the daringer/asus-fan#44 (comment) and maybe other posts in the referred issue as well.

[Greifent]

Thanks!
Edit: I thought it worked in another way, I'll look if I can find a way to do what i have in mind

[dominiksalvet]

Please close this issue once you feel it is resolved. 😸

We can continue in the discussion if an associated question arises and we can reopen the issue then.

[dominiksalvet]

I thought it worked in another way, I'll look if I can find a way to do what i have in mind

BTW, all you need should be asus-fan-control API and hence you wouldn't need to know these details... That also prevents from breaking afc-gui after modification of asus-fan-control internals. This is the reason why public APIs exist.

[Greifent]

What do you mean with asus-fan-control API?
I had in mind to show the live temperature of the computer in the GUI, I think that we misunderstood each other

[dominiksalvet]

By API I mean the functionality accessible from a terminal. E.g., asus-fan-control help, asus-fan-control get-temps, etc. are part of the asus-fan-control API.

[Greifent]

Thanks