A class to control a model R/C servo, using a PwmOut

Fork of Servo by Simon Ford

Servo.h

Committer:
simon
Date:
2009-11-16
Revision:
0:24148c673250
Child:
2:8995c167f399

File content as of revision 0:24148c673250:

/* mbed R/C Servo
 * Copyright (c) 2007-2009 sford, cstyles
 * Released under the MIT License: http://mbed.org/license/mit
 */
  
#ifndef MBED_SERVO_H
#define MBED_SERVO_H

#include "mbed.h"

/* Class: Servo
 *  Abstraction on top of PwmOut to control the position of a servo motor
 *
 * Example:
 * > // Continuously sweep the servo through it's full range
 * > #include "mbed.h"
 * > #include "Servo.h"
 * >
 * > Servo myservo(p21);
 * >
 * > int main() {
 * >     while(1) {
 * >         for(int i=0; i<100; i++) {
 * >             myservo = i/100.0;
 * >             wait(0.01);
 * >         }
 * >         for(int i=100; i>0; i--) {
 * >             myservo = i/100.0;
 * >             wait(0.01);
 * >         }
 * >     }
 * > }
 */
class Servo {

public:
    /* Constructor: Servo
     *  Create a servo object connected to the specified PwmOut pin
     *
     * Variables:
     *  pin - PwmOut pin to connect to 
     */
    Servo(PinName pin);
    
    /* Function: write
     *  Set the servo position, normalised to it's full range
     *
     * Variables:
     *  percent - A normalised number 0.0-1.0 to represent the full range.
     */
    void write(float percent);
    
    /* Function: read
     *  Read the servo motors current position
     *
     * Variables:
     *  returns - A normalised number 0.0-1.0  representing the full range.
     */
    float read();
    
    /* Function: position
     *  Set the servo position
     *
     * Variables:
     *  degrees - Servo position in degrees
     */
    void position(float degrees);
    
    /* Function: calibrate
     *  Allows calibration of the range and angles for a particular servo
     *
     *
     * Variables:
     *  range - Pulsewidth range from center (1.5ms) to maximum/minimum position in seconds
     *  degrees - Angle from centre to maximum/minimum position in degrees
     */
    void calibrate(float range = 0.0005, float degrees = 45.0); 
        
    /* Function: operator=
     *  Shorthand for the write and read functions
     */
    Servo& operator= (float percent);
    Servo& operator= (Servo& rhs);
    operator float();

protected:
    PwmOut _pwm;
    float _range;
    float _degrees;
    float _p;
};



#endif