#include LiquidCrystal lcd(7, 8, 9, 10, 11, 12); int analogInput = 0; float vout = 0.0; float vin = 0.0; float R1 = 100000.0; // resistance of R1 (100K) -see text! float R2 = 10000.0; // resistance of R2 (10K) - see text! int value = 0; void setup(){ pinMode(analogInput, INPUT); begin(16, 2); print("DC VOLTMETER"); } void loop(){ // read the value at analog input value = analogRead(analogInput); vout = (value * 5.0) / 1024.0; // see text vin = vout / (R2/(R1+R2)); if (vin<0.09) { vin=0.0;//statement to quash undesired reading ! } setCursor(0, 1); print("INPUT V= "); print(vin) delay(500); }