Arduino Bargraph Display

• Arduino Uno board
• 330 Ohm resistor = 10 Nos
• Bargrpah display
• 1 K ohm potentiometer

• The bargraph display is connected to the Arduino (2,3,4,5,6,7,8,9,10,11) digital IO pins through 330 ohm current limiting resistors.
• The potentiometer is connected to the Arduino ADC (A0) pin for simulating the signal strength.
• The potential read by the 10 bit ADC, (1024 steps ) is mapped to 0 to 10 scale and correspondingly activating the LED’s at the Bargraph display in increasing order.
• Real life scenario, the signal strength is read by the ADC, accordingly bargraph is activated for visual representation.

/*
  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 array.
  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.
 http://www.arduino.cc/en/Tutorial/BarGraph
 */
// 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);
    }
  }
}