IBT2.h

00001 /* mbed IBT-2 H-bridge motor controller
00002  * Copyright (c) 2015, rwunderl, http://mbed.org
00003  *
00004  * Permission is hereby granted, free of charge, to any person obtaining a copy
00005  * of this software and associated documentation files (the "Software"), to deal
00006  * in the Software without restriction, including without limitation the rights
00007  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00008  * copies of the Software, and to permit persons to whom the Software is
00009  * furnished to do so, subject to the following conditions:
00010  *
00011  * The above copyright notice and this permission notice shall be included in
00012  * all copies or substantial portions of the Software.
00013  *
00014  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00015  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00016  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00017  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00018  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00019  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00020  * THE SOFTWARE.
00021  */
00022 
00023 #ifndef MBED_IBT2_H
00024 #define MBED_IBT2_H
00025 
00026 #include "mbed.h"
00027  
00028 /** Interface to the IBT-2 H-bridge motor controller
00029  *
00030  * Control a DC motor connected to the IBT-2 H-bridge using one of two modes:
00031  *
00032  * Mode 1:
00033  *     2 PwmOuts and 1 DigitalOut
00034  *     - L_PWM controlled with a PwmOut
00035  *     - R_PWM controlled with a PwmOut
00036  *     - L_EN, R_EN connected to a DigitalOut (High is Enabled)
00037  *
00038  * Mode 2:
00039  *     1 PwmOut and 2 DigitalOuts
00040  *     - L_PWM connected to a DigitalOut (High is Forward; keep R_PWM Low)
00041  *     - R_PWM connected to a DigitalOut (High is Reverse; keep L_PWM Low)
00042  *     - L_EN, R_EN controlled with a PwmOut
00043  *
00044  * For now, only Mode 1 is used.
00045  */
00046 class IBT2 {
00047 public:
00048     /** Create an IBT-2 control interface    
00049      *
00050      * @param L_pwm A PwmOut pin, driving the L_PWM H-bridge line to control the forward speed.
00051      * @param R_pwm A PwmOut pin, driving the R_PWM H-bridge line to control the reverse speed.
00052      * @param en A DigitalOut pin, driving the L_EN and R_EN H-bridge enable lines.
00053      * @param freq The frequency of the H-bridge PWM lines in Hz.
00054      */
00055     IBT2(PinName L_pwm, PinName R_pwm, PinName en, float freq);
00056     
00057     /** Set the speed and direction of the motor
00058      * 
00059      * @param speed The speed of the motor as a normalized value between -1.0 and 1.0. Use a positive value for forward and a negative value for reverse.
00060      */
00061     void setSpeed(float speed);
00062     
00063     /** Get the speed and direction of the motor
00064      * 
00065      * @returns The speed of the motor as a normalized value between -1.0 and 1.0. A positive value is forward and a negative value is reverse.
00066      */
00067     float getSpeed(void);
00068 
00069 protected:
00070     PwmOut _L_pwm;
00071     PwmOut _R_pwm;
00072     DigitalOut _en;
00073     float _period;
00074     float _speed;
00075 };
00076 
00077 #endif /* MBED_IBT2_H */