A device for taking pressure readings on a HVAC system includes a first needle connectable in communication with the HVAC system for taking a first pressure reading thereof. The first needle is mounted within a first gauge and configured to self-calibrate. The device further includes a second needle connectable in communication with the HVAC system for taking a second pressure reading thereof that is independent of the first pressure reading. The second needle is mounted within a second gauge and configured to self-calibrate. A first stepper motor actuates the first needle and a second stepper motor actuates the second needle. A microcontroller controls the first and second stepper motors to move the needles to a plurality of respective positions and thereby visually confirm calibration.