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      1 /*
      2  * Author: Yevgeniy Kiveisha <yevgeniy.kiveisha (at) intel.com>
      3  * Copyright (c) 2014 Intel Corporation.
      4  *
      5  * Permission is hereby granted, free of charge, to any person obtaining
      6  * a copy of this software and associated documentation files (the
      7  * "Software"), to deal in the Software without restriction, including
      8  * without limitation the rights to use, copy, modify, merge, publish,
      9  * distribute, sublicense, and/or sell copies of the Software, and to
     10  * permit persons to whom the Software is furnished to do so, subject to
     11  * the following conditions:
     12  *
     13  * The above copyright notice and this permission notice shall be
     14  * included in all copies or substantial portions of the Software.
     15  *
     16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
     17  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
     18  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
     19  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
     20  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
     21  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
     22  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
     23  */
     24 #pragma once
     25 
     26 #include <string>
     27 #include <mraa/pwm.h>
     28 
     29 namespace upm {
     30 
     31 #define MIN_PULSE_WIDTH             600
     32 #define MAX_PULSE_WIDTH             2500
     33 #define PERIOD                      20000
     34 
     35 #define HIGH                        1
     36 #define LOW                         0
     37 
     38 #define DEFAULT_WAIT_DISABLE_PWM    0
     39 
     40 /**
     41  * @brief Servo library
     42  *
     43  * The base Servo class provides routines for setting the angle of the shaft
     44  * as well as setting and getting the minimum and maximum pulse width and
     45  * the maximum period.
     46  *
     47  * @defgroup servo libupm-servo
     48  * @ingroup seeed emax pwm servos gsk
     49  */
     50 class Servo {
     51     public:
     52         /**
     53          * Instantiates a Servo object
     54          *
     55          * @param pin Servo pin number
     56          */
     57         Servo (int pin);
     58 
     59         /**
     60          * Instantiates a Servo object
     61          *
     62          * @param pin Servo pin number
     63          * @param minPulseWidth Minimum pulse width, in microseconds
     64          * @param maxPulseWidth Maximum pulse width, in microseconds
     65          */
     66         Servo (int pin, int minPulseWidth, int maxPulseWidth);
     67 
     68         /**
     69          * Instantiates a Servo object
     70          *
     71          * @param pin Servo pin number
     72          * @param minPulseWidth Minimum pulse width, in microseconds
     73          * @param maxPulseWidth Maximum pulse width, in microseconds
     74          * @param waitAndDisablePwm If 1, PWM is enabled only during the setAngle() execution
     75          * for a period of 1 second, and then turned back off. If 0, PWM remains on afterward.
     76          */
     77         Servo (int pin, int minPulseWidth, int maxPulseWidth, int waitAndDisablePwm);
     78 
     79         /**
     80          * Servo object destructor
     81          */
     82         ~Servo();
     83 
     84         /**
     85          * Sets the angle of the servo engine.
     86          *
     87          * @param angle Number between 0 and 180
     88          * @return 0 if successful, non-zero otherwise
     89          */
     90         mraa_result_t setAngle (int angle);
     91 
     92         /**
     93          * Halts PWM for this servo and allows it to move freely.
     94          */
     95         mraa_result_t haltPwm ();
     96 
     97         /**
     98          * Returns the name of the component
     99          *
    100          * @return Name of the component
    101          */
    102         std::string name()
    103         {
    104             return m_name;
    105         }
    106 
    107         /**
    108          * Sets the minimum pulse width
    109          *
    110          * @param width Minimum HIGH signal width
    111          */
    112         void setMinPulseWidth (int width);
    113 
    114         /**
    115          * Sets the maximum pulse width
    116          *
    117          * @param width Maximum HIGH signal width
    118          */
    119         void setMaxPulseWidth (int width);
    120 
    121         /**
    122          * Sets the maximum period width
    123          *
    124          * @param period PWM period width
    125          */
    126         void setPeriod (int period);
    127 
    128         /**
    129          * Returns the minimum pulse width
    130          *
    131          * @return Minimum pulse width
    132          */
    133         int getMinPulseWidth ();
    134 
    135         /**
    136          * Returns the maximum pulse width
    137          *
    138          * @return Maximum pulse width
    139          */
    140         int getMaxPulseWidth ();
    141 
    142         /**
    143          * Returns the maximum PWM period width
    144          *
    145          * @return Maximum PWM period width
    146          */
    147         int getPeriod ();
    148 
    149     protected:
    150         int calcPulseTraveling (int value);
    151 
    152         std::string         m_name;
    153         int                 m_servoPin;
    154         float               m_maxAngle;
    155         mraa_pwm_context    m_pwmServoContext;
    156         int                 m_currAngle;
    157 
    158         int                 m_minPulseWidth;
    159         int                 m_maxPulseWidth;
    160         int                 m_period;
    161 
    162         int                 m_waitAndDisablePwm;
    163 
    164     private:
    165         void init (int pin, int minPulseWidth, int maxPulseWidth, int waitAndDisablePwm);
    166 };
    167 
    168 }
    169