The temperature of thermal_zone4 is 100000 for Jetson-nano!

Robotics & Edge Computing Jetson & Embedded Systems Jetson Nano
1

Hi nvidia:

I want to know the temperature of Jetson-nano, and executed the following commands:

jetson-nano:~$ cat /sys/class/thermal/thermal_zone0/type
AO-therm

jetson-nano:~$ cat /sys/class/thermal/thermal_zone0/temp
38500

jetson-nano:~$ cat /sys/class/thermal/thermal_zone1/type
CPU-therm

jetson-nano:~$ cat /sys/class/thermal/thermal_zone1/temp
36000

jetson-nano:~$ cat /sys/class/thermal/thermal_zone2/type
GPU-therm

jetson-nano:~$ cat /sys/class/thermal/thermal_zone2/temp
31000

jetson-nano:~$ cat /sys/class/thermal/thermal_zone3/type
PLL-therm

jetson-nano:~$ cat /sys/class/thermal/thermal_zone3/temp
29000

jetson-nano:~$ cat /sys/class/thermal/thermal_zone4/type
PMIC-Die

jetson-nano:~$ cat /sys/class/thermal/thermal_zone4/temp
100000

jetson-nano:~$ cat /sys/class/thermal/thermal_zone5/type
thermal-fan-est

jetson-nano:~$ cat /sys/class/thermal/thermal_zone5/temp
32500

Now we can see the temperature is normal except thermal_zone4(PMIC-Die) whose temperature is 100000.

Why the temperature of thermal_zone4 is 100000? Is it abnormal?

Best regards!

3

hello insomnia,

please check developer guide. you may check Thermal Management in Linux session for reference,
please also refer to Thermal Specifications for more details.
thanks

4

Hi, JerryChang

Thank you very much for your suggestion.

But I still don’t understand why the temperature of thermal_zone4 is 100000? While the other thermal zone’s temperature looks normal.

The temperature of thermal_zone5 is 32500, so the real temperature is 32.5°C.

And is the temperature of thermal_zone4 really 100°C?

Best regards!

5

No, it is not a real temperature, but it is normal.

6

Hi, Honey_Patouceul!

Thank you very much for your reply.

Thermal_zone4 is for PMIC-Die, but why the temperature of PMIC is 100°C?

Is it the reason of the temperature sensor on PMIC is not connected to jetson-nano module?

Best regards!

7

hello insomnia,

according to Topic 44422, thermal_zone4 is not the value read from PMIC but a value used by driver;
this value is fixed to 100C to illustrate the temp of PMIC.
thanks

1 Like
8

Hi, JerryChang!

Thank you very much!

Best regards!