Hide minor edits - Show changes to markup
// Set the outputs to run the motor forward
// Brake the motor
// Set the outputs to run the motor backward
This example shows the simplest thing you can do with an Arduino Due and an Arduino Motor Shield, driving a DC motor in forward and backward directions.
(:div class=BOM :)
(:divend:)
To build the circuit you need to mount the Arduino Motor Shield on top of the Arduino Due. Then you have to connect the two wires that comes out of the DC motor to the screw drivers terminals of the Motor Shield channel A. Last thing connect your wall wart power supply adapter to the DC connector of the Arduino Due. You must choose it respecting the voltage requirements of your DC motor. With the fan that we used in this example we provided 12V to the board.
Then plug your Arduino board into your computer, start the Arduino IDE 1.5, and enter the code below.

Arduino Due, Motor Shield and fan connected together
(:source lang=arduino tabwidth=4:) const int PWM_A = 3, DIR_A = 12, BRAKE_A = 9, SNS_A = A0;
void setup() {
// Configure the A output pinMode(BRAKE_A, OUTPUT); // Brake pin on channel A pinMode(DIR_A, OUTPUT); // Direction pin on channel A
// Open Serial communication
Serial.begin(9600);
Serial.println("Motor shield DC motor Test:\n");
}
void loop() {
digitalWrite(BRAKE_A, LOW); // setting brake LOW disable motor brake digitalWrite(DIR_A, HIGH); // setting direction to HIGH the motor will spin forward
analogWrite(PWM_A, 255); // Set the speed of the motor, 255 is the maximum value
delay(5000); // hold the motor at full speed for 5 seconds
Serial.print("current consumption at full speed: ");
Serial.println(analogRead(SNS_A));
Serial.println("Start braking\n");
// raising the brake pin the motor will stop faster than the stop by inertia
digitalWrite(BRAKE_A, HIGH); // raise the brake
delay(5000);
Serial.println("Backward");
digitalWrite(BRAKE_A, LOW); // setting againg the brake LOW to disable motor brake
digitalWrite(DIR_A, LOW); // now change the direction to backward setting LOW the DIR_A pin
analogWrite(PWM_A, 255); // Set the speed of the motor
delay(5000);
Serial.print("current consumption backward: ");
Serial.println(analogRead(SNS_A));
// now stop the motor by inertia, the motor will stop slower than with the brake function analogWrite(PWM_A, 0); // turn off power to the motor
Serial.print("current brake: ");
Serial.println(analogRead(A0));
Serial.println("End of the motor shield test with DC motors. Thank you!");
while(1);
}
(:sourceend:)