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Connecting LED Bar to the Arduino UNO

November 14, 2021 by share Open-Tech

Virtual Arduino Simulator - LED Bar graph


LED Bar project

In this project, LED bar is used to show the analog value read on the LED bar beautifully. 

// Your code here
Wokwi-Arduino-UNO-LED Bars.gif

Wokwi Arduino Simulator - LED Bar part simulation


  LED bar graph

  Turns on a series of LEDs based on the value of an analog sensor.
  This is a simple way to make a bar graph display. Though this graph uses 10
  LEDs, you can use any number by changing the LED count and the pins in the

  This method can be used to control any series of digital outputs that depends
  on an analog input.

  The circuit:
  - LEDs from pins 2 through 11 to ground

  created 4 Sep 2010
  by Tom Igoe

  This example code is in the public domain.

// these constants won't change:
const int analogPin = A0;   // the pin that the potentiometer is attached to
const int ledCount = 10;    // the number of LEDs in the bar graph

int ledPins[] = {
  2, 3, 4, 5, 6, 7, 8, 9, 10, 11
};   // an array of pin numbers to which LEDs are attached

void setup() {
  // loop over the pin array and set them all to output:
  for (int thisLed = 0; thisLed < ledCount; thisLed++) {
    pinMode(ledPins[thisLed], OUTPUT);

void loop() {
  // read the potentiometer:
  int sensorReading = analogRead(analogPin);
  // map the result to a range from 0 to the number of LEDs:
  int ledLevel = map(sensorReading, 0, 1023, 0, ledCount);

  // loop over the LED array:
  for (int thisLed = 0; thisLed < ledCount; thisLed++) {
    // if the array element's index is less than ledLevel,
    // turn the pin for this element on:
    if (thisLed < ledLevel) {
      digitalWrite(ledPins[thisLed], HIGH);
    // turn off all pins higher than the ledLevel:
    else {
      digitalWrite(ledPins[thisLed], LOW);

Questions on Arduino Simulator?

The below article answers the following questions

  • How to draw and connect using wires?
  • How to add a part in the Wokwi Simulator?
  • How to change wire colours?
  • How to delete a part on Wokwi?
  • How to move, rotate parts on the Wokwi Simulator and more


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share Open-Tech

Hardware enthusiast with ample interest in Arduino projects

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