/* Program 10-1 DC Motor Control
 *  
 * H-bridge driver TB6612FNG consists of four half-bridge circuit.
 * A half-bridge output can be high or low. 
 * When M1 output is high and M2 output is low, the current flows through
 * the motor from M1 to M2. When M1 is low and M2 is high, the current 
 * flows through the motor from M2 to M1 and the DC motor will reverse
 * the direction. When both of them are high or both of them are low, 
 * there is not current flowing through the motor and the motor stops.
 * 
 * The PWM pins controls the power applied to the motor. In this program,
 * the PWM pins are kept on at 100%.
 */
 
const int M1 = 2;          /* motor control pins */
const int M2 = 3;
const int PWM12 = 5;       /* PWM power control for M1 and M2 */
 
void setup() {
    /* make motor control pins output */
    pinMode(M1, OUTPUT);
    pinMode(M2, OUTPUT);
    
    /* enable motor output with PWM at 100% */
    pinMode(PWM12, OUTPUT);
    digitalWrite(PWM12, HIGH);
}
 
void loop() {
    /* current flows from M1 to M2 */
    digitalWrite(M1, HIGH);
    digitalWrite(M2, LOW);
    delay(1000);
    /* current flow stops */
    digitalWrite(M1, HIGH);
    digitalWrite(M2, HIGH);
    delay(500);
    /* current flows from M2 to M1 */
    digitalWrite(M1, LOW);
    digitalWrite(M2, HIGH);
    delay(1000);
    /* current flow stops */
    digitalWrite(M1, HIGH);
    digitalWrite(M2, HIGH);
    delay(500);
}