Hello guys, I have a big problem here. I know it's not the first npn sensor thread but I swear this time is different from the others.
Details:
° I'm using a NPN E3Z-D62 Omron photoelectric sensor (12-24 VDC). And I want to use it with my arduino Nano. I know I have to make a voltage divider, that's not the problem.
° I'm using a 12V LiPo battery for the sensors and for the arduino (supplied by a 5V regulator). My point is: They both has the same GND.
Problem:
Now, after getting 5V from the NPN sensor (Voltage divider circuit) I supposed I have to connect the 5v node to the Arduino's input and the NPN sensor's output (middle pin) direct to Arduino's GND. Circuit Diagram attached below.
As the Sensor datasheet says, the result of the sensing will be shown as a Voltage measure between the (+) 12v pin and output (middle) pin. That's what the datasheet calls the LOAD, which is placed between (+) and output.
BUT!, I noticed that the voltage between the sensor's output and (-) GND pins is not 0V!!!!!!!! It's 0.07V without detection and 0.17v when detecting objects!!!!!!!! That's the reason I can't connect the Output pin to the Arduino's GND. I would be shorting 0.17v and 0v, as the Arduino GND is the same ad the Sensor GND.
NPN Sensor datasheet: http://media.digikey.com/pdf/Data%20Sheets/Omron%20PDFs/E3Z.pdf
I really hope you guys can help this lonely soul 
