Created December 3, 2019 © GPL3+

Digital Arduino Voltmeter

A Voltmeter or a Voltage Meter is a measuring instrument that is used for measuring voltage.

Intermediate13

Things used in this project

Hardware components

Arduino UNO

Adafruit RGB Backlight LCD - 16x2

Single Turn Potentiometer- 10k ohms

Resistor 100k ohm

Resistor 10k ohm

Software apps and online services

Arduino IDE

Story

To overcome the drawbacks of analog voltmeters, Digital Voltmeters are presented. Rather than only scaling and pointing to show a measured voltage like as analog voltmeter, digital voltmeters directly display the measured voltage on the digital display.

Circuit Design

Pin 1 and Pin 2 (Vss and Vdd) of the LCD power supply are the pins for display. They are attached to ground and +5V supply respectively. Pin 3 (Vee) of the LCD is connected to the wiper terminal of the 10KΩ POT and the other terminals of the POT are connected to +5V supply and ground respectively.

The next 3 pins of the LCD are control pins. Pin 4 and Pin 6 of the LCD are attached to digital input/output pins 2 and 3 of Arduino respectively. Pin 5 (RW) of the LCD is attached to the ground.

Pin 15 (LED+) of the LCD is connected to +5V supply via a current limiting resistor of 220Ω. Pin 16 (LED-) of the LCD is attached to the ground.

The output of the voltage divider circuit consisting of 100KΩ resistor and 10KΩ resistor is attached to the analog input pin A0 of the Arduino UNO with another end of the 100KΩ resistor attached to the voltage to be calculated and the other end of the 10KΩ resistor attached to the ground.

Working

In a digital voltmeter, the voltages to be estimated, which are in analog form, are switched to digital form with the help of Analog to Digital Converters (ADC). Hence, the ADC specialty of the Arduino UNO is used in this project.

The span of voltages for Arduino Uno's analog input is 0V to 5V. Hence, in order to improve this range, a voltage divider circuit need to be used.

With the help of the voltage divider circuit, the input voltage being calculated is taken down to the range of Arduino UNOs analog input.

Arduino Digital Voltmeter

IoT Course will help you to build all such Industrial IoT Solutions.

Run a program

/*
DC Voltmeter 
*/
#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);
   lcd.begin(16, 2);
   lcd.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 !
} 
lcd.setCursor(0, 1);
lcd.print("INPUT V= ");
lcd.print(vin);
delay(500);
}

Credits

hIOTron

78 projects • 2 followers

hIOTron is an internet of things based company that offers an IoT Platform, products, IoT Solutions, and IoT Training.

Digital Arduino Voltmeter

Things used in this project

Hardware components

Software apps and online services

Story

Code

Run a program

Credits

hIOTron

Comments

Embed the widget on your own site

Digital Arduino Voltmeter

Digital Arduino Voltmeter

Things used in this project

Hardware components

Software apps and online services

Story

Code

Run a program

Credits

hIOTron

Comments

Related channels and tags