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 "Callback.h"
00021 #include "toolchain.h"
00022 
00023 namespace mbed {
00024 
00025 /** A Ticker is used to call a function at a recurring interval
00026  *
00027  *  You can use as many seperate Ticker objects as you require.
00028  *
00029  * @Note Synchronization level: Interrupt safe
00030  *
00031  * Example:
00032  * @code
00033  * // Toggle the blinking led after 5 seconds
00034  *
00035  * #include "mbed.h"
00036  *
00037  * Ticker timer;
00038  * DigitalOut led1(LED1);
00039  * DigitalOut led2(LED2);
00040  *
00041  * int flip = 0;
00042  *
00043  * void attime() {
00044  *     flip = !flip;
00045  * }
00046  *
00047  * int main() {
00048  *     timer.attach(&attime, 5);
00049  *     while(1) {
00050  *         if(flip == 0) {
00051  *             led1 = !led1;
00052  *         } else {
00053  *             led2 = !led2;
00054  *         }
00055  *         wait(0.2);
00056  *     }
00057  * }
00058  * @endcode
00059  */
00060 class Ticker : public TimerEvent {
00061 
00062 public:
00063     Ticker() : TimerEvent() {
00064     }
00065 
00066     Ticker(const ticker_data_t *data) : TimerEvent(data) {
00067         data->interface->init();
00068     }
00069 
00070     /** Attach a function to be called by the Ticker, specifiying the interval in seconds
00071      *
00072      *  @param func pointer to the function to be called
00073      *  @param t the time between calls in seconds
00074      */
00075     void attach(Callback<void()> func, float t) {
00076         attach_us(func, t * 1000000.0f);
00077     }
00078 
00079     /** Attach a member function to be called by the Ticker, specifiying the interval in seconds
00080      *
00081      *  @param obj pointer to the object to call the member function on
00082      *  @param method pointer to the member function to be called
00083      *  @param t the time between calls in seconds
00084      *  @deprecated
00085      *      The attach function does not support cv-qualifiers. Replaced by
00086      *      attach(callback(obj, method), t).
00087      */
00088     template<typename T, typename M>
00089     MBED_DEPRECATED_SINCE("mbed-os-5.1",
00090         "The attach function does not support cv-qualifiers. Replaced by "
00091         "attach(callback(obj, method), t).")
00092     void attach(T *obj, M method, float t) {
00093         attach(callback(obj, method), t);
00094     }
00095 
00096     /** Attach a function to be called by the Ticker, specifiying the interval in micro-seconds
00097      *
00098      *  @param fptr pointer to the function to be called
00099      *  @param t the time between calls in micro-seconds
00100      */
00101     void attach_us(Callback<void()> func, timestamp_t t) {
00102         _function.attach(func);
00103         setup(t);
00104     }
00105 
00106     /** Attach a member function to be called by the Ticker, specifiying the interval in micro-seconds
00107      *
00108      *  @param tptr pointer to the object to call the member function on
00109      *  @param mptr pointer to the member function to be called
00110      *  @param t the time between calls in micro-seconds
00111      *  @deprecated
00112      *      The attach_us function does not support cv-qualifiers. Replaced by
00113      *      attach_us(callback(obj, method), t).
00114      */
00115     template<typename T, typename M>
00116     MBED_DEPRECATED_SINCE("mbed-os-5.1",
00117         "The attach_us function does not support cv-qualifiers. Replaced by "
00118         "attach_us(callback(obj, method), t).")
00119     void attach_us(T *obj, M method, timestamp_t t) {
00120         attach_us(Callback<void()>(obj, method), t);
00121     }
00122 
00123     virtual ~Ticker() {
00124         detach();
00125     }
00126 
00127     /** Detach the function
00128      */
00129     void detach();
00130 
00131 protected:
00132     void setup(timestamp_t t);
00133     virtual void handler();
00134 
00135 protected:
00136     timestamp_t         _delay;     /**< Time delay (in microseconds) for re-setting the multi-shot callback. */
00137     Callback<void()>    _function;  /**< Callback. */
00138 };
00139 
00140 } // namespace mbed
00141 
00142 #endif