Arduino MKR ZERO&INA 219 Voltage Issuse

[leo_li]

Dear All，
Recently, when I was using Arduino MKR ZERO and INA219 chip modules for current and voltage test, I did not connect the power supply, but the voltage was still 0.9V, I couldn't find the problem, could someone help me?

Thanks a lot！

[jim-p]

@leo_li

INA219 chip modules

Please provide a datasheet and schematic for this module.

[Wawa]

@leo_li

I did not connect the power supply, but the voltage was still 0.9V

Makes sense.
The pin that measures voltage is currently connected to an aerial (the power wires).
A "floating" input picks up noise from the environment, and can return anything.
Try holding one of the power wires to ground of the INA, and see if it still reads 0.9volt.

Note that with an INA you must share ground of what you're measuring with ground of the Arduino.
Leo..