Gpio connect

Projects General Guidance
1

Hi,

I'm trying to connect an external gpio output to arduino.
The external gpio outputs the on/off status of a lamp.

Measuring the external gpio (gpio pin - > ground) it gives 0.26V when off and 26mV when on.

How do I safely connect this output to Arduino. Om afraid a pull-down resistor might overload the external Gpio port.

Is there a solution to make a passive switch so both units are isolated?

2

No answer because you have not given information - Web links to specifications, description of the device, photographs etc. - regarding what this "external gpio" actually is. :roll_eyes:

Called the "XY problem",