Ticker.h

00001 /* mbed Microcontroller Library - Ticker
00002  * Copyright (c) 2007-2009 ARM Limited. All rights reserved.
00003  */ 
00004  
00005 #ifndef MBED_TICKER_H
00006 #define MBED_TICKER_H
00007 
00008 #include "TimerEvent.h"
00009 #include "FunctionPointer.h"
00010 
00011 namespace mbed {
00012 
00013 /** A Ticker is used to call a function at a recurring interval
00014  *
00015  *  You can use as many seperate Ticker objects as you require. 
00016  *
00017  * Example:
00018  * @code
00019  * // Toggle the blinking led after 5 seconds
00020  *
00021  * #include "mbed.h"
00022  * 
00023  * Ticker timer;
00024  * DigitalOut led1(LED1);
00025  * DigitalOut led2(LED2);
00026  * 
00027  * int flip = 0;
00028  * 
00029  * void attime() {
00030  *     flip = !flip;
00031  * }
00032  *
00033  * int main() {
00034  *     timer.attach(&attime, 5);
00035  *     while(1) {
00036  *         if(flip == 0) {
00037  *             led1 = !led1;
00038  *         } else {
00039  *             led2 = !led2;
00040  *         }
00041  *         wait(0.2);
00042  *     }
00043  * }
00044  * @endcode
00045  */
00046 class Ticker : public TimerEvent {
00047 
00048 public:
00049 
00050     /** Attach a function to be called by the Ticker, specifiying the interval in seconds
00051      *     
00052      *  @param fptr pointer to the function to be called
00053      *  @param t the time between calls in seconds
00054      */
00055     void attach(void (*fptr)(void), float t) {
00056         attach_us(fptr, t * 1000000.0f);
00057     }
00058     
00059     /** Attach a member function to be called by the Ticker, specifiying the interval in seconds
00060      *     
00061      *  @param tptr pointer to the object to call the member function on
00062      *  @param mptr pointer to the member function to be called
00063      *  @param t the time between calls in seconds
00064      */
00065     template<typename T>
00066     void attach(T* tptr, void (T::*mptr)(void), float t) {
00067         attach_us(tptr, mptr, t * 1000000.0f);
00068     }
00069     
00070     /** Attach a function to be called by the Ticker, specifiying the interval in micro-seconds
00071      *     
00072      *  @param fptr pointer to the function to be called
00073      *  @param t the time between calls in micro-seconds
00074      */
00075     void attach_us(void (*fptr)(void), unsigned int t) {
00076         _function.attach(fptr);
00077         setup(t);
00078     }
00079 
00080     /** Attach a member function to be called by the Ticker, specifiying the interval in micro-seconds
00081      *     
00082      *  @param tptr pointer to the object to call the member function on
00083      *  @param mptr pointer to the member function to be called
00084      *  @param t the time between calls in micro-seconds
00085      */    
00086     template<typename T>
00087     void attach_us(T* tptr, void (T::*mptr)(void), unsigned int t) {
00088         _function.attach(tptr, mptr);
00089         setup(t);
00090     }
00091     
00092     /** Detach the function
00093      */        
00094     void detach();
00095 
00096 protected:
00097 
00098     void setup(unsigned int t);
00099     virtual void handler();
00100 
00101     unsigned int _delay;
00102     FunctionPointer _function;
00103 
00104 };
00105 
00106 } // namespace mbed
00107 
00108 #endif