top of page

Building a Digital Voltmeter using Arduino UNO.

Updated: Mar 19

Digital Voltmeter is a testing instrument that is used to measure the electrical potential difference between two points in a circuit and displays the measured voltage values in the discrete numeric form.

Now, in this article let us attempt to design the Digital voltmeter using Arduino UNO in the TinkerCAD simulation software.

Simulation software is an interactive tool generally used in experimenting with the circuit design before establishing it in the hardware/PCB board. It helps to analyze the design schematic, to check the integrity of its functions and makes sure of the efficiency of the design before establishing it in the circuit board.

Let's first start with the requirements that we will need to design the circuit with TinkerCAD Software.

Hardware Requirements:

These components are required for manual circuit development, for #simulation purposes TinkerCAD software is sufficient. To build the circuit manually, click on the links given below to buy the components required.

1. Breadboard


A breadboard is an essential component that is in a rectangular shape with small holes in it that are used to insert the components to test the circuits. The connections are not fixed and can be varied. In a breadboard, the holes in one horizontal line are in series connection with each other. Breadboards are made from plastic or wood and come in all shapes, sizes, and even different colors, the most commonly used sizes for designing the circuits are "full-size," "half-size," and "mini" breadboards.

Buy Breadboard from here.

2. Arduino UNO

Develop a stronger concept in Arduino through this article:- What is Arduino?

Arduino UNO
Arduino UNO

#Arduino board is a microcontroller that accepts inputs from sensors connected and provides an output action on the desired device connected to it. The sensor inputs can be from light-detecting sensors, motion sensors (Ultrasonic or IR), temperature sensors, etc. The output from this device can be received through devices such as LED, Buzzer, Serial monitor, etc.

Buy Arduino UNO from here.

3. 16*2 LCD Display

16*2 LCD Display
16*2 LCD Display

16*2 #LCD Display is a basic electronic display module in various devices and circuits. It has 16 pins that include a ground pin, supply pin, contrast control, register select, read/write, enable, Data pin 0 to 7, LED+5V and, LED-Ground.

Buy 16*2 LCD Display from here.

4. DC Power Supply

DC Power Supply
DC Power Supply

The power supply is essential, electronic devices that are used to convert AC power to DC power output. It constantly supplies the DC voltage to its load.

Buy DC Power Supply from here.

5. Resistor


Resistors are passive devices that restrict the flow of current or divide the voltage through the circuit. The input power passes through these resistors and then to the sensors to avoid damage. Here in this project, 220 ohm, 1M ohm, and 10K resistors are used.

Buy Resistors from here.

6. Jumper Wires

Jumper Wires
Jumper Wires

These are the main components that are used to establish the connections between different devices of the circuit. There are three types male to female, female to female, and male to male.

Buy Jumper Wires from here.

7. USB Cable

USB Cable
USB Cable

This cable is used to connect the development boards to the power supply. It also helps in the transmission of data.

Buy USB Cable from here.

Software Requirements:

1. TinkerCAD Software:

TinkerCAD Software LOGO
TinkerCAD Software LOGO

It is an easy-to-use online simulation #software used for circuit design. It has all the essential electrical components required to built and analyze the circuit.

Visit the TinkerCad website.

Circuit Connection and its Working:

The circuit connection involves the following steps:

  • First, we will start with the connection of LCD, Connect the Data PIN 4,5,6, and 7 to the 5,4,3,2 Digital pins of the Arduino board.

  • The supply pin (VCC) is connected to the positive terminal of the breadboard.

  • Connect the RS and Enable pins of the LCD to the 11th and 12th pins of the Arduino Board respectively.

  • Then, connect the GND pin, Vo pin, RW pin, and one LED pin of the LCD to the negative terminals of the breadboard.

  • Connect another LED pin to one terminal of the 220-ohm resistor and the other terminal is grounded.

  • Two resistors R1= 1M ohm and R2= 10K ohm resistors are used to build a voltage divider circuit to maximize the voltage readings range.

  • Connect the positive end of the power supply terminal to the one end of the 1M ohm resistor and the other end to the 10K ohm resistor. And another end of the 10K ohm resistor is grounded.

  • The negative end of the power supply terminal is connected to the negative terminal of the breadboard.

  • From the junction of two resistors, a terminal is connected to the analog PIN A0 of the Arduino board.

  • Finally, the GND pin of the Arduino pin is connected to the negative terminal of the breadboard to establish a common ground connection. Then, the VCC- 5 volts of the Arduino is also connected to the positive terminal of the breadboard respectively.



Let us first learn how to work with TinkerCAD #simulation software. Once entered on the TinkerCAD page, select circuits, and search for the components required for the connection. The required components are to be dragged and brought to the circuiting screen. The connection needs to be made by selecting the jumper wires. Different colors of wire can be selected to distinguish between each connection.

Learn more about TinkerCad in detail.

Upload the code and start the simulation to see the output in the LCD display.

The Voltage reading in the numeric form is displayed on the LCD screen. The input voltage can be changed accordingly for the desired output.

Watch the working video for the practical explanation of designing the circuit and to know more about how the simulation software works.

Check the Project working video here - Building a Digital Voltmeter using Arduino UNO.

Video By - Sri Harshita.

Simulation software plays a major role in the building of large circuits as they help to analyze the working of the circuit before it can be built practically. It helps us create a virtual design of the circuit we want to build and avoid damages to the circuit if in case we don't know, beforehand about the correct circuit connections.

For more projects through TinkerCad click here.

By using this TinkerCad open-source software design your own circuit, run the code in the software, and validate your project ideas.


See Also:

Related Posts

See All


LearnElectronics India's explanation is spot-on. Great work!


Anushka Gupta
Anushka Gupta
Jul 25, 2023

This blog is a treasure trove of information for anyone interested in Arduino and electronics. I appreciate the effort taken by the author to provide detailed explanations, making complex concepts seem approachable. This project has ignited a new passion for electronics within me.

bottom of page