Ticker.h

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2006-2013 ARM Limited
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 #ifndef MBED_TICKER_H
00017 #define MBED_TICKER_H
00018 
00019 #include "TimerEvent.h"
00020 #include "FunctionPointer.h"
00021 
00022 namespace mbed {
00023 
00024 /** A Ticker is used to call a function at a recurring interval
00025  *
00026  *  You can use as many seperate Ticker objects as you require.
00027  *
00028  * Example:
00029  * @code
00030  * // Toggle the blinking led after 5 seconds
00031  *
00032  * #include "mbed.h"
00033  *
00034  * Ticker timer;
00035  * DigitalOut led1(LED1);
00036  * DigitalOut led2(LED2);
00037  *
00038  * int flip = 0;
00039  *
00040  * void attime() {
00041  *     flip = !flip;
00042  * }
00043  *
00044  * int main() {
00045  *     timer.attach(&attime, 5);
00046  *     while(1) {
00047  *         if(flip == 0) {
00048  *             led1 = !led1;
00049  *         } else {
00050  *             led2 = !led2;
00051  *         }
00052  *         wait(0.2);
00053  *     }
00054  * }
00055  * @endcode
00056  */
00057 class Ticker : public TimerEvent {
00058 
00059 public:
00060 
00061     /** Attach a function to be called by the Ticker, specifiying the interval in seconds
00062      *
00063      *  @param fptr pointer to the function to be called
00064      *  @param t the time between calls in seconds
00065      */
00066     void attach(void (*fptr)(void), float t) {
00067         attach_us(fptr, t * 1000000.0f);
00068     }
00069 
00070     /** Attach a member function to be called by the Ticker, specifiying the interval in seconds
00071      *
00072      *  @param tptr pointer to the object to call the member function on
00073      *  @param mptr pointer to the member function to be called
00074      *  @param t the time between calls in seconds
00075      */
00076     template<typename T>
00077     void attach(T* tptr, void (T::*mptr)(void), float t) {
00078         attach_us(tptr, mptr, t * 1000000.0f);
00079     }
00080 
00081     /** Attach a function to be called by the Ticker, specifiying the interval in micro-seconds
00082      *
00083      *  @param fptr pointer to the function to be called
00084      *  @param t the time between calls in micro-seconds
00085      */
00086     void attach_us(void (*fptr)(void), unsigned int t) {
00087         _function.attach(fptr);
00088         setup(t);
00089     }
00090 
00091     /** Attach a member function to be called by the Ticker, specifiying the interval in micro-seconds
00092      *
00093      *  @param tptr pointer to the object to call the member function on
00094      *  @param mptr pointer to the member function to be called
00095      *  @param t the time between calls in micro-seconds
00096      */
00097     template<typename T>
00098     void attach_us(T* tptr, void (T::*mptr)(void), unsigned int t) {
00099         _function.attach(tptr, mptr);
00100         setup(t);
00101     }
00102 
00103     /** Detach the function
00104      */
00105     void detach();
00106 
00107 protected:
00108     void setup(unsigned int t);
00109     virtual void handler();
00110 
00111     unsigned int _delay;
00112     FunctionPointer _function;
00113 };
00114 
00115 } // namespace mbed
00116 
00117 #endif