The original VI used an “x-y” graph to display the input voltage applied to the Arduino Uno. The x-y graph was replaced with an analog meter to make a virtual instrument DC voltmeter.
I’ve also added a Hi Limit LED along with a reference control to the original virtual instrument design. The reference control is used to set a threshold detection input voltage to be applied to the Arduino Uno’s A0 pin. If the input voltage exceeds the reference voltage, the Hi Limit LED will turn ON. The stop button stops the execution of the analog voltmeter VI. The block diagram shows the comparator circuit, reference control, and Hi Limit LED added to the original virtual instrument design. The analog voltmeter VI can be obtained at the bottom of the article in the Download Code box.