I read from the thermal design guide:
“Note that reading internal nodes utilizes internal CPU resources. Thus, accessing the nodes too frequently will incur excessive amount of power consumption due to this reading task. It is recommended to set the sample interval to 1 second or longer.”

Could someone explain what is the internal CPU resources referred here and why is that limitation imposed and if there is any way to overcome it and use higher frequency like a KHz for sampling the power consumption. What is the underlying principle that limits this for the INA3221 monitors?

Thank you.

INA3221 is I2C device, I2C read/write operation do need CPU resources, do frequently I2C read will make CPU can’t not go to idle state and running at relative higher frequency increase power consumption.
The power monitor INA3221 on Jetson is design to set threshold give SOC interrupt to limit frequency or shut system when over current, not for power consumption measurement.
Need external DAQ device to do accurate power measurement if need.