Does PWM fan automatically spins when temp. is reached?

Robotics & Edge Computing Jetson & Embedded Systems Jetson Nano
1

Hello!
I have few of PWM fans since yesterday but haven’t seen them spinning so far, does Nano’s B01 dev. board sends a PWM signal when some temperature threshold is reached or until I put the script fans will remain “dead” ?
If so: that would mean that I have to myself check temperature programmatically in regular intervals ?

3

hello JoskoZadar,

please refer to documentation, Thermal Zone.
you may configure trip points in the device tree to change the thermal actions.
in addition, you may also enable tegrastats utility to monitor system usage and also thermal reports.
thanks

4

Thanks!
It seems documentation for Nano lacks some clarifying details about fan:

  • For thermal zone “thermal-fan-est” says only that it is “supported”, but is it activated by default as well so fan automatically kicks in when temp. reached 51° C , or is to be activated by user?

  • This code snippet for modifying “thermal-zone-params”, in which file is it exactly placed? Plain file search discovers same named folder structure but nothing like that in the file-content itself?

  • Two fan modes can be set on Xavier (cool or quiet) but these modes seem not to be mentioned in Nano docs. When trying to execute it on Nano ( nvpmodel -d cool ) it says “Fan failed to set mode: cool”. These modes are not applicable to Nano ?

5

I have just improvised one test myself with a hair blow-dryer (making Nano reach higher temps) and seems “thermal-fan-est” is enabled by default…

But question #2 remains?

6

hello JoskoZadar,

please access L4T sources via download center.
you may check below for Nano’s thermal zone definitions.
for example,
$L4T_Sources/r32.4.3/Linux_for_Tegra/source/public/hardware/nvidia/platform/t210/porg/kernel-dts/porg-platforms/tegra210-porg-thermal.dtsi

you may also refer to Building the NVIDIA Kernel and also Flashing a Specific Partition to update device tree independently.
thanks