How to Use L293D Motor Driver: Examples, Pinouts, and Specs

The L293D is a dual H-bridge motor driver IC designed to control the direction and speed of DC motors and stepper motors. It is capable of driving two motors simultaneously, making it an essential component in robotics, automation, and motor control projects. The IC can handle bidirectional control of motors, allowing for forward and reverse motion, and supports pulse-width modulation (PWM) for speed control. Its compact design and ease of use make it a popular choice for hobbyists and professionals alike.

• Robotics (e.g., controlling robot wheels)
• Conveyor belt systems
• Automated gates and doors
• Stepper motor control in CNC machines
• DIY motorized projects

The L293D is a robust IC with the following key specifications:

The L293D has 16 pins, as described in the table below:

1. Power Connections:

   • Connect Vcc1 (Pin 16) to a 5V power supply for the logic circuit.
   • Connect Vcc2 (Pin 8) to the motor power supply (4.5V to 36V, depending on the motor).
   • Connect all GND pins (Pins 4, 5, 12, 13) to the ground of the power supply.

2. Motor Connections:

   • Connect the motor terminals to the output pins (OUT1, OUT2 for Motor 1; OUT3, OUT4 for Motor 2).

3. Control Logic:

   • Use the input pins (IN1, IN2 for Motor 1; IN3, IN4 for Motor 2) to control the direction of the motors.
   • Use the enable pins (EN1 for Motor 1; EN2 for Motor 2) to enable/disable the motors or to control speed using PWM.

4. Direction Control:

   • Set the input pins as follows to control motor direction:
     • IN1 = HIGH, IN2 = LOW: Motor 1 moves forward.
     • IN1 = LOW, IN2 = HIGH: Motor 1 moves backward.
     • IN1 = IN2: Motor 1 stops.

5. Speed Control:

   • Apply a PWM signal to the enable pins (EN1 or EN2) to control motor speed.

Below is an example of how to control a DC motor using the L293D and Arduino UNO:

// Define motor control pins
const int ENA = 9;  // Enable pin for Motor 1 (connected to PWM pin)
const int IN1 = 2;  // Input 1 for Motor 1
const int IN2 = 3;  // Input 2 for Motor 1

void setup() {
  // Set motor control pins as outputs
  pinMode(ENA, OUTPUT);
  pinMode(IN1, OUTPUT);
  pinMode(IN2, OUTPUT);
}

void loop() {
  // Move motor forward
  digitalWrite(IN1, HIGH);  // Set IN1 HIGH
  digitalWrite(IN2, LOW);   // Set IN2 LOW
  analogWrite(ENA, 200);    // Set speed (0-255)

  delay(2000);              // Run for 2 seconds

  // Stop motor
  digitalWrite(IN1, LOW);   // Set IN1 LOW
  digitalWrite(IN2, LOW);   // Set IN2 LOW
  analogWrite(ENA, 0);      // Set speed to 0

  delay(1000);              // Wait for 1 second

  // Move motor backward
  digitalWrite(IN1, LOW);   // Set IN1 LOW
  digitalWrite(IN2, HIGH);  // Set IN2 HIGH
  analogWrite(ENA, 150);    // Set speed (0-255)

  delay(2000);              // Run for 2 seconds

  // Stop motor
  digitalWrite(IN1, LOW);
  digitalWrite(IN2, LOW);
  analogWrite(ENA, 0);

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

• Ensure the motor power supply voltage matches the motor's specifications.
• Use a heat sink if the IC gets too hot during operation.
• Avoid exceeding the maximum current rating to prevent damage to the IC.
• Decouple the power supply with capacitors to reduce noise and voltage spikes.

1. Motor Not Running:

   • Check power supply connections to Vcc1 and Vcc2.
   • Ensure the enable pin (EN1 or EN2) is set to HIGH or receiving a PWM signal.
   • Verify the input logic pins (IN1, IN2, etc.) are correctly configured.

2. Motor Running in the Wrong Direction:

   • Reverse the logic levels on the input pins (e.g., swap IN1 and IN2).

3. IC Overheating:

   • Ensure the current drawn by the motor does not exceed 600mA.
   • Use a heat sink or reduce the motor load.

4. PWM Speed Control Not Working:

   • Verify the PWM signal is being sent to the correct enable pin.
   • Check the PWM frequency and duty cycle settings in your microcontroller code.

Q: Can the L293D drive stepper motors?
A: Yes, the L293D can drive stepper motors by controlling the sequence of inputs to the H-bridges.

Q: Can I use the L293D with a 3.3V microcontroller?
A: The L293D requires a minimum logic voltage of 4.5V. Use a level shifter or a 5V microcontroller for compatibility.

Q: How many motors can the L293D control?
A: The L293D can control two DC motors or one stepper motor.