Android - Spinner, onItemSelected(...) not being called

It might be the spinner layouts, I can see you didn't set a dropdown view for the adapter. Could you try to initialize your spinner like this:

deviceAdapter = new DeviceAdapter(this, android.R.layout.simple_spinner_item, deviceList);
deviceSpinner.setAdapter(deviceAdapter);
deviceAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
deviceSpinner.setOnItemSelectedListener(this);