Arduino Voltmeter

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

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

Instruction;
1) Connect all jumper wire as shown in diagram.

Upload this code to your arduino

/*
Voltmeter
Voltmeter base on voltage divider concept.

*/

// include the library code:
#include

// 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);
lcd.print(“Vin=”);
}

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);
lcd.print(vin);
lcd.print(“V”);

// sleep…
delay(500);
}