Best accurate place to read nano voltage

for jetson nano
voltage range is 4.75v ~ 5.25v

so is :
cat /sys/bus/i2c/drivers/ina3221x/6-0040/iio:device0/in_voltage0_input

the best accurate place to read it ?

Hi jd13,

Are you using the devkit or custom board?
What’s your Jetpack version in use?

Yes, you can read that for the voltage of VDD_IN.
You can find more details in Power Management for Jetson Nano and Jetson TX1 Devices