Servo.h

00001 /* mbed R/C Servo Library
00002  * Copyright (c) 2007-2010 sford, cstyles
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_SERVO_H
00024 #define MBED_SERVO_H
00025 
00026 #include "mbed.h"
00027 
00028 /** Servo control class, based on a PwmOut
00029  *
00030  * Example:
00031  * @code
00032  * // Continuously sweep the servo through it's full range
00033  * #include "mbed.h"
00034  * #include "Servo.h"
00035  * 
00036  * Servo myservo(p21);
00037  * 
00038  * int main() {
00039  *     while(1) {
00040  *         for(int i=0; i<100; i++) {
00041  *             myservo = i/100.0;
00042  *             wait(0.01);
00043  *         }
00044  *         for(int i=100; i>0; i--) {
00045  *             myservo = i/100.0;
00046  *             wait(0.01);
00047  *         }
00048  *     }
00049  * }
00050  * @endcode
00051  */
00052 class Servo {
00053 
00054 public:
00055     /** Create a servo object connected to the specified PwmOut pin
00056      *
00057      * @param pin PwmOut pin to connect to 
00058      */
00059     Servo(PinName pin);
00060     
00061     /** Set the servo position, normalised to it's full range
00062      *
00063      * @param percent A normalised number 0.0-1.0 to represent the full range.
00064      */
00065     void write(float percent);
00066     
00067     /**  Read the servo motors current position
00068      *
00069      * @param returns A normalised number 0.0-1.0  representing the full range.
00070      */
00071     float read();
00072     
00073     /** Set the servo position
00074      *
00075      * @param degrees Servo position in degrees
00076      */
00077     void position(float degrees);
00078     
00079     /**  Allows calibration of the range and angles for a particular servo
00080      *
00081      * @param range Pulsewidth range from center (1.5ms) to maximum/minimum position in seconds
00082      * @param degrees Angle from centre to maximum/minimum position in degrees
00083      */
00084     void calibrate(float range = 0.0009, float degrees = 90.0); 
00085         
00086     /**  Shorthand for the write and read functions */
00087     Servo& operator= (float percent);
00088     Servo& operator= (Servo& rhs);
00089     operator float();
00090 
00091 protected:
00092     PwmOut _pwm;
00093     float _range;
00094     float _degrees;
00095     float _p;
00096 };
00097 
00098 #endif