Control a DC motor via a standard H-bridge using a PwmOut pin to control speed and two DigitalOut pins to control direction. Can change pwm period on the PwmOut pin, and also brake high or low.

Dependents:   SimpleRover PIDRover IMURover incrementalencoder-pid-robot ... more

Motor.h

Committer:
aberk
Date:
2010-09-07
Revision:
1:c75b234558af
Parent:
0:f05e09f8f5d9

File content as of revision 1:c75b234558af:

/* mbed simple H-bridge motor controller
 * Copyright (c) 2007-2010, sford
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#ifndef MBED_MOTOR_H
#define MBED_MOTOR_H

#include "mbed.h"

#define BRAKE_HIGH 1
#define BRAKE_LOW  0

/** Interface to control a standard DC motor 
 * with an H-bridge using a PwmOut and 2 DigitalOuts
 */
class Motor {
public:

    /** Create a motor control interface    
     *
     * @param pwm A PwmOut pin, driving the H-bridge enable line to control the speed
     * @param fwd A DigitalOut, set high when the motor should go forward
     * @param rev A DigitalOut, set high when the motor should go backwards
     */
    Motor(PinName pwm, PinName fwd, PinName rev);
    
    /** Set the speed of the motor
     * 
     * @param speed The speed of the motor as a normalised value between -1.0 and 1.0
     */
    void speed(float speed);
    
    /** Set the period of the pwm duty cycle.
     *
     * Wrapper for PwmOut::period()
     *
     * @param seconds - Pwm duty cycle in seconds.
     */
    void period(float period);
    
    /** Brake the H-bridge to GND or VCC.
     * 
     * Defaults to breaking to VCC.
     *
     * Brake to GND => inA = inB = 0
     * Brake to VCC => inA = inB = 1
     */
    void brake(int highLow = BRAKE_HIGH);

protected:
    PwmOut _pwm;
    DigitalOut _fwd;
    DigitalOut _rev;

};

#endif