Arduino Voltmeter Code

This arduino projects show how to make voltmeter with your arduino. It use voltage divider concept to estimate the voltage input.

Arduino Voltmeter

1) Connect all jumper wire as shown in diagram.

Upload this code to your arduinoArduino Voltmeter

  Voltmeter base on voltage divider concept.

  Code based on:
  Coded by:

// include the library code:
#include <LiquidCrystal.h>

// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(7, 8, 9, 10, 11, 12);

// variables for input pin and control LED
  int analogInput = 1;
  float vout = 0.0;
  float vin = 0.0;
  float R1 = 50000.0;    // !! resistance of R1 !!
  float R2 = 4400.0;     // !! resistance of R2 !!

// variable to store the value 
  int value = 0;

void setup(){
  // declaration of pin modes
  pinMode(analogInput, INPUT);

  // set up the LCD's number of columns and rows:
  lcd.begin(16, 2);

void loop(){
  // read the value on analog input
  value = analogRead(analogInput);

  vout = (value * 5.0) / 1024.0;
  vin = vout / (R2/(R1+R2));  

  // print result to lcd display
  lcd.setCursor(4, 0);

  // sleep...

a) You might saw some reading 0.06V even there is no Vin supply, this may caused by signal noise. You can add if statement to flush this reading. ie

if (vin<0.09) {
add before print result to lcd display line.

[box color=”#985D00″ bg=”#FFF8CB” font=”verdana” fontsize=”14 ” radius=”20 ” border=”#985D12″ float=”right” head=”Major Components in Project” headbg=”#FFEB70″ headcolor=”#985D00″]Parts List;
1) 1x 16×2 parallel LCD display (compatible with Hitachi HD44780 driver)
2) 1x Arduino
3) 1x 10kΩ potentiometer
4) 5x 10kΩ resistor
5) 2x 2.2kΩ resistor
6) Jumper wire[/box]

For more detail: Arduino Voltmeter Code

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  • arduino voltmeter
  • java read voltmeter code
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