This project demonstrates how to control the speed and direction of a DC motor using an L293D motor driver chip and Arduino's Pulse Width Modulation (PWM) capabilities. This setup allows for precise motor control, making it suitable for a variety of applications.

Here are some project ideas using this setup:

• Robotics: Control the movement of a small robot's wheels.
• Automated devices: Create automated curtains, blinds, or a small conveyor belt.
• Fan control: Adjust the speed of a cooling fan based on temperature readings.
• Solar trackers: Position small solar panels to follow the sun throughout the day.

Hardware/Components

• Arduino Uno (or compatible board)
• L293D Motor Driver IC
• DC Motor (rated for the L293D's voltage and current limits, up to 600mA)
• 9V Power Supply (for the motor)
• Connecting wires
• Breadboard (recommended)

Wiring Guide

The L293D chip acts as an interface between the Arduino and the DC motor. It allows the Arduino to control both the motor's speed and direction. The chip requires a separate power supply for the motor because the Arduino cannot supply enough current for most motors. (in video at 04:04)

Code Explanation

The Arduino code controls the L293D driver, which in turn controls the DC motor. The code uses PWM to vary the motor speed, and digital signals to switch direction.

Here are the key configurable parameters in the code:

#define P1A 10 // Arduino pin connected to L293D input 1A
#define P2A 11 // Arduino pin connected to L293D input 2A
#define EN12 9 // Arduino pin connected to L293D enable pin (1,2EN)

const int speedStep = 15; // Increment for speed changes
const int speedDelay = 1000; // Delay between speed steps (in milliseconds)

The L293D() function controls the motor's direction and speed. 'L' sets the motor to rotate clockwise, 'R' sets it to counter-clockwise. The spd parameter controls the speed (0-255) and en enables (1) or disables (0) the motor. (in video at 09:24)

void L293D(char dir,int spd, int en)
{
  if(dir =='L') // Clockwise rotation
  {
    // ...
    analogWrite(P1A,spd); // Set speed using PWM
    digitalWrite(P2A,LOW); 
  }else{ // Counter-clockwise rotation
    // ...
    digitalWrite(P1A,LOW);
    analogWrite(P2A,spd); // Set speed using PWM
  }
}

Live Project/Demonstration

The video demonstrates the project in action, showing the motor speed and direction changes. The oscilloscope readings visualize the PWM signals controlling the motor. (in video at 11:07)

Chapters

• [00:00] Introduction to DC Motor Control with L293D
• [00:30] Project Demonstration and Explanation
• [01:12] L293D Motor Driver Overview
• [02:08] DC Motor Specifications
• [02:30] L293D Datasheet Explanation
• [04:40] Wiring Explanation and Demonstration
• [07:05] Arduino Code Explanation
• [11:07] Project Demonstration and Oscilloscope Readings