Fan Module for Arduino L9110 Big Chip

// wired connections

#define HG7881_B_IA 10 // D10 --> Motor B Input A --> MOTOR B +

#define HG7881_B_IB 11 // D11 --> Motor B Input B --> MOTOR B -

// functional connections

#define MOTOR_B_PWM HG7881_B_IA // Motor B PWM Speed

#define MOTOR_B_DIR HG7881_B_IB // Motor B Direction

// the actual values for "fast" and "slow" depend on the motor

#define PWM_SLOW 50  // arbitrary slow speed PWM duty cycle

#define PWM_FAST 200 // arbitrary fast speed PWM duty cycle

#define DIR_DELAY 1000 // brief delay for abrupt motor changes

void setup()

{

  Serial.begin( 9600 );

  pinMode( MOTOR_B_DIR, OUTPUT );

  pinMode( MOTOR_B_PWM, OUTPUT );

  digitalWrite( MOTOR_B_DIR, LOW );

  digitalWrite( MOTOR_B_PWM, LOW );

}

void loop()

{

  boolean isValidInput;

  // draw a menu on the serial port

  Serial.println( "-----------------------------" );

  Serial.println( "MENU:" );

  Serial.println( "1) Fast forward" );

  Serial.println( "2) Forward" );

  Serial.println( "3) Soft stop (coast)" );

  Serial.println( "4) Reverse" );

  Serial.println( "5) Fast reverse" );

  Serial.println( "6) Hard stop (brake)" );

  Serial.println( "-----------------------------" );

  do

  {

    byte c;

    // get the next character from the serial port

    Serial.print( "?" );

    while( !Serial.available() )

      ; // LOOP...

    c = Serial.read();

    // execute the menu option based on the character recieved

    switch( c )

    {

      case '1': // 1) Fast forward

        Serial.println( "Fast forward..." );

        // always stop motors briefly before abrupt changes

        digitalWrite( MOTOR_B_DIR, LOW );

        digitalWrite( MOTOR_B_PWM, LOW );

        delay( DIR_DELAY );

        // set the motor speed and direction

        digitalWrite( MOTOR_B_DIR, HIGH ); // direction = forward

        analogWrite( MOTOR_B_PWM, 255-PWM_FAST ); // PWM speed = fast

        isValidInput = true;

        break;      

      case '2': // 2) Forward      

        Serial.println( "Forward..." );

        // always stop motors briefly before abrupt changes

        digitalWrite( MOTOR_B_DIR, LOW );

        digitalWrite( MOTOR_B_PWM, LOW );

        delay( DIR_DELAY );

        // set the motor speed and direction

        digitalWrite( MOTOR_B_DIR, HIGH ); // direction = forward

        analogWrite( MOTOR_B_PWM, 255-PWM_SLOW ); // PWM speed = slow

        isValidInput = true;

        break;      

      case '3': // 3) Soft stop (preferred)

        Serial.println( "Soft stop (coast)..." );

        digitalWrite( MOTOR_B_DIR, LOW );

        digitalWrite( MOTOR_B_PWM, LOW );

        isValidInput = true;

        break;      

      case '4': // 4) Reverse

        Serial.println( "Fast forward..." );

        // always stop motors briefly before abrupt changes

        digitalWrite( MOTOR_B_DIR, LOW );

        digitalWrite( MOTOR_B_PWM, LOW );

        delay( DIR_DELAY );

        // set the motor speed and direction

        digitalWrite( MOTOR_B_DIR, LOW ); // direction = reverse

        analogWrite( MOTOR_B_PWM, PWM_SLOW ); // PWM speed = slow

        isValidInput = true;

        break;      

      case '5': // 5) Fast reverse

        Serial.println( "Fast forward..." );

        // always stop motors briefly before abrupt changes

        digitalWrite( MOTOR_B_DIR, LOW );

        digitalWrite( MOTOR_B_PWM, LOW );

        delay( DIR_DELAY );

        // set the motor speed and direction

        digitalWrite( MOTOR_B_DIR, LOW ); // direction = reverse      

        analogWrite( MOTOR_B_PWM, PWM_FAST ); // PWM speed = fast

        isValidInput = true;

        break;

      case '6': // 6) Hard stop (use with caution)

        Serial.println( "Hard stop (brake)..." );

        digitalWrite( MOTOR_B_DIR, HIGH );

        digitalWrite( MOTOR_B_PWM, HIGH );

        isValidInput = true;

        break;      

      default:

        // wrong character! display the menu again!

        isValidInput = false;

        break;

    }

  } while( isValidInput == true );

  // repeat the main loop and redraw the menu...

}