Arduino Projects

Digital Voltmeter using Arduino & 16×2 LCD

If you work with electronics you definitely need some necessary equipment. like voltmeter but, what if you don’t have one? What a nightmare! But don’t worry, you can use Arduino as a digital voltmeter.
🙂 Yes, isn’t it exciting?


So today we will learn to make a Digital Voltmeter using Arduino & 16×2 LCD and Arduino IDE. Due to covid-19, I was unable to visit the market and buy a simple voltmeter to check the voltage of a battery for some of my projects, that I have been working on. Therefore, I decided to make a simple Arduino based voltmeter project that can help you a lot in this pandemic situation. So, without doing any delay let’s get started with Voltmeter using the Arduino project.

Digital Voltmeter using Arduino

Components Required:

Following are the components Required for making Digital Voltmeter using Arduino & 16×2 LCD at your home:

  • Arduino UNO
  • 16×2 I2C LCD Display
  • Few Male to Female and Male to Male jumper wires

Note: For probes, we will use Male to Male jumper wires

Circuit diagram of Digital Voltmeter using Arduino

Now, assemble the circuit as shown in the circuit diagram below:

Circuit Diagram of Digital Voltmeter using Arduino & 16x2 LCD
Circuit Diagram

Connect Vcc and GND Pin of 16×2 I2C LCD to 5volt and GND Pin of the Arduino UNO. Now, Connect SCL and SDA Pin of I2C LCD to A5 and A4 pin respectively as shown in the above diagram. Similarly, attach two Male to Male jumper wires as a probes to GND and A0 Pin of Arduino UNO. Finally, attach the USB cable to the Arduino board and PC to upload the program code.

Program code:

Copy this program code in your Arduino IDE program. Now select your Arduino board and COM Port from the tools menu. Compile the code and upload it to Arduino.

#include <LiquidCrystal_I2C.h>

float vol = 0;
int input = 0;

LiquidCrystal_I2C lcd(0x27, 16, 2);   // set the LCD address to 0x27 for a 16 chars and 2 line display

void setup() {

  lcd.init();                          // initialize the lcd
  lcd.setCursor(1, 0);
  lcd.setCursor(0, 1);
  lcd.print("By - The ");
  lcd.setCursor(0, 1);
  lcd.print("IoT Projects");        // Don't Forget to Subscribe on YouTube ------ The IoT Projects :)
  pinMode(A0, INPUT);
  Serial.begin(9600);               // starting the Serial Monitor

void loop() {
  input = analogRead(A0);          //analogRead function is used to recive analog data
  vol = (input * 5.0) / 1024.0;    //formula using for perform action
  lcd.print("voltage is:");
  lcd.setCursor(0, 1);


Demonstration of Digital Voltmeter using Arduino & 16×2 LCD

Now, its time to test the project. This Arduino based digital voltmeter shows around 1.5-1.8 volts when not connected and 0 volts when probes touch each other.

Arduino based Digital Voltmeter

I have tested the project with some dead batteries, partially charged batteries, and fully charged batteries. It works as expected but, it cannot calculate the negative voltage. 

Just watch the video to Find out How to make a digital voltmeter using Arduino and 16×2 I2C LCD Display.


So, today we have learned to make Digital Voltmeter using Arduino & 16×2 LCD in a step by step manner. I hope this simple project will help you a lot. That’s all for today, Stay safe, stay healthy, and stay at home. See you soon.

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