This routine seems that is not working any more
B4X:
Sub MacAddress() As Byte()
RunNative("getMac", Null)
Return macarray
End Sub
#if C
#include <ESP8266WiFi.h>
void getMac(B4R::Object* u) {
WiFi.macAddress((Byte*)b4r_wifiserver::_macarray->data);
}
#end if