A long time ago, i wrote a little tutorial on how to use a L298 Dual H-bridge motor driver, but i thought i could go further and this time I tried with a L293D chip.

The L293D Chip is a Dual H-Bridge Motor Driver for DC or Step motors. It can handle two Motors or one step motor. It can power motors until 36V and 600mA of steady current  – Max of 1.2A.

The chip is easy to use and takes little space

In this tutorial will see how to use it to power 1 or 2 DC Motors

NOTE: If you don’t want to mess with ICs and need a more easy approach, I recommend Grove I2C Motor Driver from Seeed. It’s easy to use and very straightforward. (about seeed)

In a few weeks, I will create something awesome with it. Keep in touch

Requirements

  • L293D chip
  • Arduino (I’m using UNO)
  • 2x DC Motors
  • 4x AA batteries and holder

First, here’s the chip

L293D

and the specs – the darker small semi-circle is on the TOP –

learn_raspberry_pi_L293D

A little explanation on the Chip PINs

NOTE: As you can see, L293D as two power PINs – 8 (+Vmotor) and 16 (+V). The PIN 8 provides power for the motors ( Separate power source) and the PIN 16 provides power for the chip (provided by the Arduino)

Motor control PINs

EN1 Enable Motor 1
EN2 Enable Motor 2
IN1 Direction 1 Motor A
IN2 Direction 2 Motor A
IN3 Direction 1 Motor B
IN4 Direction 2 Motor B

PIN values and meaning to the bridge and motors

PIN Value
IN1 HIGH Enables Motor A
LOW Disables Motor A
IN2 HIGH Enables Motor B
LOW Disables Motor B
IN1 HIGH Motor A Forward
IN2 LOW
IN1 LOW Motor A Backwards
IN2 HIGH
IN1 LOW Motor A Stops
IN2 LOW
IN1 HIGH
IN2 HIGH

The same happens when using EN3 and EN4

Wiring

The wiring is simple, but requires atention. Here’s a schematic from Fritzing (click the image for a bigger version)

l293d_arduino_bb

A table with the connections

L293 PIN Arduino PIN
EN1 5
IN1 6
IN2 7
EN2 8
IN3 9
IN4 10

NOTE: In the code i’ve used digitalWrite to enable the IN(x) PINs, but you can use analogWrite (and change INx PINS to PWM PINs) and use values from 0-255 to control speed.

Coding

Here’s the code for the programm

/**
* Bruno Santos, 2013
* feiticeir0@whatgeek.com.pt
* Small code to test DC motors - 2x with a L298 Dual H-Bridge Motor Driver
* Free to share
**/

//Testing the DC Motors with
// L293D

//Define Pins
//Motor A
int enableA = 5;
int MotorA1 = 6;
int MotorA2 = 7;
 
//Motor B
int enableB = 8;
int MotorB1 = 9;
int MotorB2 = 10;

void setup() {
  
  Serial.begin (9600);
  //configure pin modes
  pinMode (enableA, OUTPUT);
  pinMode (MotorA1, OUTPUT);
  pinMode (MotorA2, OUTPUT);  
  
  pinMode (enableB, OUTPUT);
  pinMode (MotorB1, OUTPUT);
  pinMode (MotorB2, OUTPUT);  
  
}

void loop() {
  //enabling motor A
  Serial.println ("Enabling Motors");
  digitalWrite (enableA, HIGH);
  digitalWrite (enableB, HIGH);
  delay (1000);
  //do something

  Serial.println ("Motion Forward");
  digitalWrite (MotorA1, LOW);
  digitalWrite (MotorA2, HIGH);

  digitalWrite (MotorB1, LOW);
  digitalWrite (MotorB2, HIGH);

  //3s forward
  delay (3000);
  
  Serial.println ("Motion Backwards");
  //reverse
  digitalWrite (MotorA1,HIGH);
  digitalWrite (MotorA2,LOW);  
  
  digitalWrite (MotorB1,HIGH);
  digitalWrite (MotorB2,LOW);  

  //5s backwards
  delay (3000);

  Serial.println ("Stoping motors");
  //stop
  digitalWrite (enableA, LOW);
  digitalWrite (enableB, LOW);
  delay (3000);
}

This way, you can use a simple chip to control 2 DC Motors.

l293d-2

Happy coding

References

http://computers.tutsplus.com/tutorials/controlling-dc-motors-using-python-with-a-raspberry-pi–cms-20051

https://learn.adafruit.com/adafruit-raspberry-pi-lesson-9-controlling-a-dc-motor/lm293d

About Seeed

Studio Seeed is the IoT hardware enabler providing services over 10 years that empower makers to realize their projects and products. Seeed offers a wide array of hardware platforms and sensor modules ready to be integrated with existing IoT platforms and one-stop PCB manufacturing and Prototype PCB Assembly. Seeed Studio provides a wide selection of electronic parts including Arduino, Raspberry Pi and many different development board platforms. Especially the Grove System help engineers and makers to avoid jumper wires problems. Seeed Studio has developed more than 280 Grove modules covering a wide range of applications that can fulfill a variety of needs.