Dynamic Motor Driver Library

This library provides functionality for two DC motor bidirectional movement and is abstracted in a way that your code can remain nearly exactly the same even if you want to change out your motor driver. The only thing you would need to change is the object you create.

For example if you have the following code

/*
 * Initialize our driver with the pins (motorA1, motorA2, motorB1, motorB2) and we're assuming:
 * Motor A = Left motor
 * Motor B = Right motor
 * The pins here would map to AIN1, AIN2, BIN1, BIN2 respectively
 */
DRV8835 driver(3, 4, 5, 6);


void setup() {
  // The only thing left to do is call init() so the library can initialize the pins
  driver.init();
    
  // Now, what we will do is just call our main code here so that it only happens once

  // Let's move the left motor forward a bit (our motor speed is valued from -100 to +100)
  driver.setMotorAPower(50);  // Set the motor speed to 50% in a forward direction
  delay(1000);                // Wait a second
  driver.motorABrake();       // Stop our motor, we can brake or coast (self explanatory right)

  // Let's move the right motor forward a bit (Motor B this time)
  driver.setMotorBPower(50);  // Set the motor speed to 50% in a forward direction
  delay(1000);                // Wait a second
 driver.motorBBrake();       // Stop our motor

  // Now let's control both motors to drive straight
  driver.setMotorAPower(50);
  driver.setMotorBPower(50);
  delay(1000);                // Wait a second
  driver.brakeAll();          // Notice here we can brake both motors using the brakeAll() function

  // That's it! Now you can see how to control each motor or both motors at the same time.
  // Feel free to change the word 'brake' with 'coast' wherever it shows up to see how coast might differ.
}

void loop() {

}

Now you want to use a new driver board, you no longer have to change your code or use a different library. Simply change the object you create as shown below where we've changed DRV8835Driver to L298

/*
 * Initialize our driver with the pins (motorA1, motorA2, motorB1, motorB2) and we're assuming:
 * Motor A = Left motor
 * Motor B = Right motor
 * The pins here would map to AIN1, AIN2, BIN1, BIN2 respectively
 */
L298 driver(3, 4, 5, 6);


void setup() {
  // The only thing left to do is call init() so the library can initialize the pins
        driver.init();
        
  // Now, what we will do is just call our main code here so that it only happens once

  // Let's move the left motor forward a bit (our motor speed is valued from -100 to +100)
  driver.setMotorAPower(50);  // Set the motor speed to 50% in a forward direction
  delay(1000);                // Wait a second
  driver.motorABrake();       // Stop our motor, we can brake or coast (self explanatory right)

  // Let's move the right motor forward a bit (Motor B this time)
  driver.setMotorBPower(50);  // Set the motor speed to 50% in a forward direction
  delay(1000);                // Wait a second
  driver.motorBBrake();       // Stop our motor

  // Now let's control both motors to drive straight
  driver.setMotorAPower(50);
  driver.setMotorBPower(50);
  delay(1000);                // Wait a second
  driver.brakeAll();          // Notice here we can brake both motors using the brakeAll() function

  // That's it! Now you can see how to control each motor or both motors at the same time.
  // Feel free to change the word 'brake' with 'coast' wherever it shows up to see how coast might differ.
}

void loop() {

}

Caveat(s)

The library will work with Arduino or Teensy boards but note that it will do nothing with the PWM frequency. If you want to adjust the PWM frequency you will have to do that outside of this library.

FAQs

Why is one motor spinning in the wrong direction?

The simplest and most proper solution is to swap the motor connections in your circuit. In many cases it is also possible to swap the pin assignments. So, if you have a motor driver defined, for example, as driver(5, 6, 7, 8) and motor A is spinning the wrong direction, you could change to driver(6, 5, 7, 8)