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:
http://elinux.org/Jetson/Jetson_TK1_Power#Measuring_the_power_draw_and_battery_level

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

http://www.phidgets.com/products.php?category=8&product_id=1135_0
http://www.phidgets.com/products.php?category=8&product_id=1122_0

Thank you dusty_nv so much!