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Lesson 98: Arduino 10 LED Push button Projects, Potentiometer LED Voltmeter and Traffic Light

Lesson 98: Arduino 10 LED Push button Projects, Potentiometer LED Voltmeter and Traffic Light

Please select other codes for this lecture from the links below.

Part 1: Introduction

In this lesson we learn how to use LED and Push button in this 10 LED projects. Wiring diagram is shown, code is fully explained and demonstrated with multiple change of settings for each project. We read potentiometer's voltage and display voltage by turning each LED on to represent voltages. A Simple traffic light project.
This code is part of video lecture. This project 9 code. This code will turn ON and OFF 5 LEDS such that only one will be turned ON using a variable resistor or Potentiometer. When the knob is rotated it looks like light is walking. you can add more LEDs to make is look fancy. 


 
/*
 * Arduino Step by Step Course by Robojax
 * Lesson 98  https://robojax.com/course1/?vid=lecture98
 * Project 9 of 10
 * 
 * LED Voltage Level Meter
 * 
 * This code will turn ON and OFF 5 LEDS such that only one will be turned ON using a variable resistor or Potentiometer. When the knob is rotated it looks like light is walking. you can add more LEDs to make is look fancy.
 * Watch full details and demonstraiton: https://youtu.be/OSwleCBlkuI
 * 
 * Start a full Arduino Step By Step course:  https://youtu.be/-6qSrDUA5a8
 * 
 ****** 10 Projects explained in this video
 * 1-LED ON OFF 
 * 2-LED ON/OFF with push button
 * 3-LED ON/OFF toggle with push button
 * 4-Fading light of LED
 * 5-Fading light of LED using push button
 * 6-See Saw with LED
 * 7-Walking Light
 * 8-Walking light with push button
 * 9-LED voltage level meter
 * 10- Arduino Traffic Light
 * 
 * LED = Light Emitting Diode
 * LED is pronouced (El EE Dee)
 * LED Voltage Bar
 * this is an Arduino that turns ON up to 5 LEDs according to
 * the voltage read by Arduino from Variable resistor (potentiometer) to 
 * pin A0
 * 
 * written by Ahmad Shamshiri on Jan 31, 2011 at 22:17 in Ajax, Ontario, Canada
 * this code can be obtained from Robojax.com
 * Code ID: WalkingLED
 This video is part of Arduino Step by Step Course which starts here: https://youtu.be/-6qSrDUA5a8

  * written by Ahmad Shamshiri on Jan 30, 2022
 * in Ajax, Ontario, Canada
 * www.Robojax.com

If you found this tutorial helpful, please support me so I can continue creating 
content like this. Make a donation using PayPal by credit card https://bit.ly/donate-robojax
  
 * This code is "AS IS" without warranty or liability. Free to be used as long as you keep this note intact.* 
 * This code has been download from Robojax.com
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.* 
 */
const int potPin = A0;//define a pin to connect potentiometer
const int LED1 = 7;
const int LED2 = 6;
const int LED3 = 5;
const int LED4 = 4;
const int LED5 = 3;

int LED_ON = LED1;
boolean showVoltage = true;//true or false to read voltage in serial monitor

float boardVoltage= 5.0;//for UNO and MEGA 5.0V for Nano either 5V or 3.3V


void setup() {
  Serial.begin(9600);
  Serial.println("LED Voltage Meter");
    Serial.print("Board voltage ");
    Serial.print(boardVoltage);  
    Serial.print("V");
  pinMode(LED1, OUTPUT);//set LED1 pin as output
  pinMode(LED2, OUTPUT);//set LED2 pin as output
  pinMode(LED3, OUTPUT);//set LED3 pin as output
  pinMode(LED4, OUTPUT);//set LED4 pin as output
  pinMode(LED5, OUTPUT);//set LED5 pin as output  
}//setup end

void loop() {

  int sensorValue = analogRead(A0);
  // Convert the analog reading (which goes from 0 - 1023) to a voltage (0 - 5V):
  float voltage = sensorValue * (boardVoltage / 1023.0);
  //  // Watch full details and demonstraiton: https://youtu.be/7xTHaFdCyaI

 if(showVoltage == true)
 {
      Serial.print("Voltage: ");      
      Serial.print(voltage);
      Serial.println("V");   
 } 
    delay(50);
  // print out the value you read:
  if (voltage >= boardVoltage*0.95)
  {
        digitalWrite(LED1, HIGH);    
        digitalWrite(LED2, HIGH);
        digitalWrite(LED3, HIGH);    
        digitalWrite(LED4, HIGH);   
        digitalWrite(LED5, HIGH);          
    
  }else if (voltage >= boardVoltage * 0.80 )
  {
        digitalWrite(LED1, HIGH);    
        digitalWrite(LED2, HIGH);
        digitalWrite(LED3, HIGH);    
        digitalWrite(LED4, HIGH);    
        digitalWrite(LED5, LOW);           
  }else if (voltage >= boardVoltage * 0.60 )
  {
        digitalWrite(LED1, HIGH);    
        digitalWrite(LED2, HIGH);
        digitalWrite(LED3, HIGH);    
        digitalWrite(LED4, LOW); 
        digitalWrite(LED5, LOW);              
  }else if (voltage >= boardVoltage * 0.40  )
  {
        digitalWrite(LED1, HIGH);    
        digitalWrite(LED2, HIGH);
        digitalWrite(LED3, LOW);    
        digitalWrite(LED4, LOW);  
        digitalWrite(LED5, LOW);             
  }else if ( voltage > boardVoltage * 0.20 )
  {
        digitalWrite(LED1, HIGH);    
        digitalWrite(LED2, LOW);
        digitalWrite(LED3, LOW);    
        digitalWrite(LED4, LOW);  
        digitalWrite(LED5, LOW);             
  }else
  {
        digitalWrite(LED1, LOW);    
        digitalWrite(LED2, LOW);
        digitalWrite(LED3, LOW);    
        digitalWrite(LED4, LOW);  
        digitalWrite(LED5, LOW);             
  }
  // Watch full details and demonstraiton: https://youtu.be/7xTHaFdCyaI
  
 }//loop end