Arduino DC Motor Speed and Direction L293D

Introduction: Arduino DC Motor Speed and Direction L293D

This instructable will guide you through the parts and steps to control a Dc motor's speed and direction with the help of a dual H-Bridge L293D motor driver for arduino.

The motor driver has two channels which means that it can controll the direction of two Dc motors simultaneously.

Let me walk you through the parts required to do this...and then the steps with codes.

Step 1: Part List

1) Arduino uno.. Original version cheaply available at

2) L293D... 5pcs available for 1.59 euros at

3) Tactile push button.. 100pcs for .99 euros at

4) 10K potentiometer...

5) Breadboard..

6) Jumper wires...

7) Computer with arduino IDE... I cannot provide link to this u know.

Step 2: L293D Pin Layout

Step 3: Breadboard Layout

NOW lets get working.

Step 4: Attach the L293D, Potentiometer and the Button Onto the Breadboard..


PIN1(Enable1) -- DigitalPin11(PWM)

PIN2(INPUT1) -- DigitalPin10(PWM)


PIN4(GND1) -- Gnd


PIN7(INPUT2) -- DigitalPin9(PWM)

PIN8(12v) -- 5v

PIN9(Vss3.3v) -- 5v/// the pin says 3.3v but u can connect it to 5v also.


Pin1(positive)-- 5v

Pin2(signal) -- analogPIN0

PIn3(negative) -- Gnd


1PIN= Gnd

2PIN = DigitalPIN7

Step 5: Arduino Code



int enablePin = 11;

int in1Pin = 10;

int in2Pin = 9;

int switchPin = 7;

int potPin = 0;

int statusPin= 13;

void setup()


pinMode(in1Pin, OUTPUT);

pinMode(in2Pin, OUTPUT);

pinMode(enablePin, OUTPUT);

pinMode(switchPin, INPUT_PULLUP);



void loop()



int speed = analogRead(potPin) / 4;

boolean reverse = digitalRead(switchPin);

setMotor(speed, reverse);


void setMotor(int speed, boolean reverse)


analogWrite(enablePin, speed);

digitalWrite(in1Pin, ! reverse);

digitalWrite(in2Pin, reverse);


Step 6: That's It Your Done!!

Turn the potentiometer to control the speed of the motor and press the button to change the direction.



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    23 Discussions

    hi sir....

    please help me...

    i am using one 12v dc motor

    raindrop sensor

    L293D driver


    i want arduino code

    the motor will run forward then stop after 30 sec on not raining condition, if raining condition the motor will run backward direction then stop after 30 sec......

    please help sir.........................

    how can we operate it in such a way that once the button is pressed it remains in reverse and if its pressed again it goes back to forward? and do we need to debounce the button for this case?

    1 reply

    You will need to use an external interrupt + hardware (or software, if you prefer) button debounce. Take a look at the attachInterrupt method.

    sir why you used statusPin in the program? What is the use of that pin?

    But you are not connected that pin to the arduino.

    First of all, i apologize for the very late reply. And the statuspin is Pin13 on the Arduino, which drives the inbuilt Led

    Hello sir,

    I am driving a 24V DC motor using arduino uno. No any special motor driver i am using.motor drives only by SPDT relay for more current requirement.but i can not control the speed of please tell me how i control the speed of motor using relay itself.or send me code of that.


    Vinod Kumbhar.

    Hi Surya,

    Thanks for this. I have very limited or no knowledge about electronics. I am doing a DIY project just by reading stuff and using my common sense. So my questions may be ... you know :-)

    I am using a 12v DC motor. I have completed the project with no electronics (relays, limit switches etc). I want to re-do the project using electronic components so that I can get more control over the working.

    I read in some other place that if I use 12V motor, I need to use transistors, diodes and capacitors to manage the current without damaging the Arduino.

    Can you confirm this and if possible, can you send me a connection diagram? Thanks.

    -- Senthil

    Thank You senthil for your comment..It is actually required to use capacitors transistors and diodes to control a 12v D.C.Motor without damaging the arduino because the arduino can only handle upto 5v input power and a 12v dc motor will produce 12v directly to the I/O pins of the arduino and it may start smoking.....You can check out this site for circuit diagram..

    Hello , I want to know how we can do it with out a switch. Can you give me any clue, please?

    1 reply

    without switch and potentiometer ? or just without the switch ?

    used this circuit as primary level project in my college thank you very much

    can someone help?

    char COM; //Variable creation

    int motor1Pin1 = 3; // pin 2 on L293D

    int motor1Pin2 = 4; // pin 7 on L293D

    int enablePin = 9; // pin 1 on L293D

    void setup()


    Serial.begin(9600); // Begins a Serial with a 9600bps Baud Rate(

    pinMode(motor1Pin1, OUTPUT);

    pinMode(motor1Pin2, OUTPUT);

    pinMode(enablePin, OUTPUT);


    void loop()


    if (Serial.available() > 0)


    COM =;

    switch (COM)


    case '8'://FORWARD

    digitalWrite(motor1Pin1,255, 1);

    digitalWrite(motor1Pin2,255, 1);

    break; // switch OFF

    case '4'://LEFT

    digitalWrite(motor1Pin1,255, 0);

    digitalWrite(motor1Pin2,255, 1);

    break; //switch OFF

    case '2'://BACK

    digitalWrite(motor1Pin1,255, 0);

    digitalWrite(motor1Pin2,255, 0);

    break; //switch OFF

    case '6'://RIGHT

    digitalWrite(motor1Pin1,255, 1);

    digitalWrite(motor1Pin2,255, 0);

    break; //switch OFF


    delay(250); // 250 mili seconds Delay

    digitalWrite(motor1Pin1,255, 1);

    digitalWrite(motor1Pin2,255, 1);

    COM = 0;



    1 reply

    this program is correct or not?

    u will execute this program?

    Thanks for this circuit - it worked well first time.

    I am however rather at a loss to understand how the motor speed is controlled through the L293D ic. I have used the pot, analog input and PWM output to control a motor but I cannot see how the pwm output controls the motor speed here.


    Ive got this working. Really helped me with a project.

    Ive upgraded to a 24v motor, and wanted to know how would we connect it without frying the L293 chip or the arduino.

    I know we would need mosfets / transistors(noobie appologies)