How to Use DRIVER SHIELD L293D: Examples, Pinouts, and Specs

The DRIVER SHIELD L293D is a motor driver shield designed for use with the Arduino platform. This shield allows for the control of up to two DC motors, enabling bi-directional rotation and providing the ability to create projects that require motorized movements such as robotics, automated machinery, and more. The L293D shield simplifies the process of controlling motors by integrating H-bridge circuits, which are essential for changing the direction of the motor's rotation.

• Robotics: Steering, driving wheels, and actuating robotic limbs.
• Automated systems: Conveyor belts, automated doors, and other machinery.
• Educational projects: Learning about motor control and H-bridge functionality.
• Prototyping: Quick setup for testing motor-driven concepts.

• Voltage (Motor Supply): 4.5V to 36V
• Voltage (Logic): 5V (from Arduino board)
• Current (Per Channel): 600mA continuous, 1.2A peak
• Channels: 2 (can control 2 DC motors)
• H-Bridge: 4 (2 H-bridges per motor)

1. Mounting the Shield: Place the L293D shield on top of the Arduino board, ensuring that all pins are aligned and properly inserted.
2. Connecting Motors: Connect the terminals of the DC motors to the Motor A and Motor B connections on the shield.
3. Power Supply: Provide an external power supply to the Vm pin if the motors require more voltage than the Arduino can supply.
4. Control Wiring: Use the control pins to send signals from the Arduino to the L293D shield for motor operation.
5. PWM Pins: Connect PWM-capable pins from the Arduino to the enable pins for speed control.

• Ensure that the power supply voltage and current ratings are within the specifications of the L293D shield to prevent damage.
• Use PWM signals for speed control to enable smooth operation of the motors.
• Always disconnect the power supply before making or altering connections to prevent accidental damage or injury.
• Include flyback diodes if using inductive loads to protect the shield from voltage spikes.

• Motor not rotating: Check connections, ensure power supply is adequate, and verify that the control signals are being sent correctly.
• Overheating: Ensure that the current draw is within the limits, and consider adding heat sinks if necessary.
• Inconsistent motor speed: Verify that the PWM signal is stable and that the power supply can handle the load without significant voltage drops.

• Double-check wiring and solder joints for any loose connections or shorts.
• Use a multimeter to verify the voltage levels at the motor terminals and control pins.
• Test the motors independently to ensure they are functioning correctly.
• Review your code to ensure that the correct pins are being addressed and that the logic is sound.

#include <Arduino.h>

// Define motor control and PWM pins
const int motorAPin1 = 10; // Control pin for motor A
const int motorAPin2 = 9;  // Control pin for motor A
const int motorBPin1 = 11; // Control pin for motor B
const int motorBPin2 = 3;  // Control pin for motor B
const int enablePinA = 5;  // PWM pin for motor A speed
const int enablePinB = 6;  // PWM pin for motor B speed

void setup() {
  // Set motor control pins as outputs
  pinMode(motorAPin1, OUTPUT);
  pinMode(motorAPin2, OUTPUT);
  pinMode(motorBPin1, OUTPUT);
  pinMode(motorBPin2, OUTPUT);
  pinMode(enablePinA, OUTPUT);
  pinMode(enablePinB, OUTPUT);
}

void loop() {
  // Rotate Motor A forward
  digitalWrite(motorAPin1, HIGH);
  digitalWrite(motorAPin2, LOW);
  analogWrite(enablePinA, 128); // Set speed (0-255)

  // Rotate Motor B reverse
  digitalWrite(motorBPin1, LOW);
  digitalWrite(motorBPin2, HIGH);
  analogWrite(enablePinB, 128); // Set speed (0-255)

  delay(2000); // Run motors for 2 seconds

  // Stop motors
  digitalWrite(motorAPin1, LOW);
  digitalWrite(motorAPin2, LOW);
  digitalWrite(motorBPin1, LOW);
  digitalWrite(motorBPin2, LOW);
  analogWrite(enablePinA, 0); // Turn off PWM to stop motor
  analogWrite(enablePinB, 0); // Turn off PWM to stop motor

  delay(1000); // Wait for 1 second
}

This example demonstrates basic forward and reverse control of two DC motors using the L293D motor driver shield. Adjust the analogWrite values to control the speed of the motors.