Rachana Jain
Published © Apache-2.0

L293D Motor Driver Shield with Arduino

Learn about how to use an L293D motor driver shield with Arduino to control the speed & direction of rotation of motor.

IntermediateFull instructions provided3 hours2,150
L293D Motor Driver Shield with Arduino

Things used in this project

Hardware components

Arduino UNO
Arduino UNO
×1
L293D Motor Driver Shield
×1
DC motor
×1
Push button
×1
POT 10kohn
×1
LCD 16x2
×1
Solderless Breadboard Full Size
Solderless Breadboard Full Size
×1
Jumper wires (generic)
Jumper wires (generic)
×1

Story

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Code

Arduino Code

Arduino
/* 
Interfacing DC Motor with Arduino UNO using L293D motor Driver shield
by www.playwithcircuit.com 
*/
#include <AFMotor.h>
  // Library to run DC Motor Using Motor Driver Shield  
#include <LiquidCrystal_I2C.h> 
  // Library to Run I2C LCD
LiquidCrystal_I2C lcd(0x27, 16, 2);  // Format -> (Address,Columns,Rows )
// Create the motor object connected to M3
AF_DCMotor motor(3);
// Define button pins
const int forwardButtonPin = A1;
const int reverseButtonPin = A2;
const int stopButtonPin    = A3;
// Define potentiometer pin
const int potPin = A0;
// Variables to store motor state and direction
bool motorRunning  = false;
int motorDirection = BACKWARD;  // FORWARD or BACKWARD
// Read the potentiometer value
int potValue;
int motorSpeed;
// Variable to store button states
bool forwardButtonState;
bool stopButtonState;
bool reverseButtonState;
// Inline function to check if button is pressed packed with debouncing logic
inline bool chkButtonState(int pinNum, int checkState, int debounceDelay) {
  if (((digitalRead(pinNum) == checkState) ? true : false) == true) {
    delay(debounceDelay);
    return (((digitalRead(pinNum) == checkState) ? (true) : (false)) == true);
  } else {
    return false;
  }
}
void setup() {
  // initialize the lcd
  lcd.init();
  // Turn on the Backlight
  lcd.backlight();
  // Clear the display buffer
  lcd.clear();
  // Set cursor (Column, Row)
  lcd.setCursor(0, 0);
  lcd.print("DC Motor using");
  lcd.setCursor(0, 1);
  lcd.print("L293D Shield");
  // Set button pins as inputs
  pinMode(forwardButtonPin, INPUT_PULLUP);
  pinMode(stopButtonPin   , INPUT_PULLUP);
  pinMode(reverseButtonPin, INPUT_PULLUP);
  // Start with motor off
  motor.setSpeed(0);
  motor.run(RELEASE);
  delay(2000);
  // Clear the display buffer
  lcd.clear();
  // Set cursor (Column, Row)
  lcd.setCursor(0, 0);
  lcd.print("Motor Direction:");
  lcd.setCursor(0, 1);
  lcd.print("Stopped   ");
}
void loop() {
  // Read the potentiometer value for changing speed as per Analog input
  potValue   = analogRead(potPin);
  motorSpeed = map(potValue, 0, 1023, 0, 255);
  // Read the button states
  forwardButtonState = chkButtonState(forwardButtonPin, LOW, 20);
  reverseButtonState = chkButtonState(reverseButtonPin, LOW, 20);
  stopButtonState    = chkButtonState(stopButtonPin,    LOW, 20);
  // check for Forward run
  if (forwardButtonState && (!motorRunning || motorDirection == BACKWARD)) {
    // Set cursor (Column, Row)
    lcd.setCursor(0, 1);
    lcd.print("Clock   ");
    if (motorDirection == BACKWARD) {
      motor.setSpeed(0);
      motor.run(RELEASE);
      delay(1000);
    }
    motorRunning = true;
    motorDirection = FORWARD;
    motor.setSpeed(motorSpeed);
    motor.run(FORWARD);
  }
  
  // check for Reverse run
  else if (reverseButtonState && (!motorRunning || motorDirection == FORWARD)) {
    // Set cursor (Column, Row)
    lcd.setCursor(0, 1);
    lcd.print("Anti-Clk");
    if (motorDirection == FORWARD) {
      motor.setSpeed(0);
      motor.run(RELEASE);
      delay(1000);
    }
    motorRunning = true;
    motorDirection = BACKWARD;
    motor.setSpeed(motorSpeed);
    motor.run(BACKWARD);
  }
  
  // Stop motor
  else if (stopButtonState && motorRunning) {
    // Set cursor (Column, Row)
    lcd.setCursor(0, 1);
    lcd.print("Stopped         ");
    motorRunning = false;
    motor.setSpeed(0);
    motor.run(RELEASE);
  }
   
  // Adjust motor speed if running and display speed on LCD
  if (motorRunning) {
    motor.setSpeed(motorSpeed);
    // Set cursor (Column, Row)
    lcd.setCursor(9, 1);
    lcd.print("SPD:");
    lcd.print(((motorSpeed*100)/255));
    lcd.print("%  ");
  }
}

Credits

Rachana Jain
18 projects • 12 followers
I'm an avid Arduino and electronics enthusiast with a passion for tinkering, experimenting, and bringing innovative ideas to life.

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