how to read current voltage on Tegra Jetson TK1

Hi. I have the board Tk1, and want to implementing the DVFS technique. I ready know how to scaling the runtime frequency and how to read the current frequency. In order to make sure the power is also changed when I scaling frequency, I want to know how to read the runtime voltage. Please!

On TK1 you’ll need external instrumentation. See here for info on how to measure it:

If you need a machine-readable sensor, I’ve used these before:

Thank you dusty_nv so much!