To Find Device serial Number from pc
If you have more than one device connected to pc, then you shluld provide the serial identifier of the device that UITest should run the tests on. You can obtain a list of the devices using the Android Debug Bridge, for this you might add variables in your compurter from properties->Advanced System Settings->Advanced->click on Environment Variable-> After adding variables follow below command $ ADB devices -> enter List of devices attached XXXXXXXXXXX device