This guide will show you how to read the junction temperature of the processor on the phyCORE-i.MX7 SOM.
Reading the Temperature
The phyCORE-i.MX7 processor has 1 physical location where the temperature can be monitored (thermal zone). The available zone can be accessed in the Linux directory /sys/class/thermal/thermal_zone0
The below command can be used to output the temperature of thermal zone 0.
root@imx7d-phyboard-zeta-004:~# cat /sys/class/thermal/thermal_zone0/temp 54000
This output translates to 54.0C
Temperature Trip Points
The thermal zone includes trip points. You can set the trip points to a temperature that will trigger an event, such as turning on a fan for active cooling. You can also build in a critical trip point; if this temperature is reached, Linux will automatically shutdown the system for protection of the processor.
To view the type of trip points and the trip point temperatures of thermal zone 0 use the following command:
root@imx7d-phyboard-zeta-004:~# cat /sys/class/thermal/thermal_zone0/trip_point* 85000 passive 90000 critical