better use basic function instead of Newping
I already used Newping to test it, but I prefere to use that
digitalWrite(TRIGGER, LOW);
delayMicroseconds(2);
digitalWrite(TRIGGER, HIGH);
delayMicroseconds(10);
digitalWrite(TRIGGER, LOW);
duration = pulseIn(ECHO, HIGH);
distance = ((duration / 2) / 29.1) * 10;