Thank you for your quick reply,
Unfortunately i don't have USB power meter. I plugged a power supply module (1PC) to a breadboard. Now I used one cable coming from the (+) point of the breadboard into the vin pin from my Arduino. The (-) point is connected to GND pin. (see picture). I also tried to measure the current put the meter in-line.
I followed this discription:
https://learn.sparkfun.com/tutorials/how-to-use-a-multimeter#measuring-current
But still no result, maybe i am doing something wrong...
