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 "drivers/TimerEvent.h"
00020 #include "platform/Callback.h"
00021 #include "platform/toolchain.h"
00022 
00023 namespace mbed {
00024 /** \addtogroup drivers */
00025 /** @{*/
00026 
00027 /** A Ticker is used to call a function at a recurring interval
00028  *
00029  *  You can use as many seperate Ticker objects as you require.
00030  *
00031  * @Note Synchronization level: Interrupt safe
00032  *
00033  * Example:
00034  * @code
00035  * // Toggle the blinking led after 5 seconds
00036  *
00037  * #include "mbed.h"
00038  *
00039  * Ticker timer;
00040  * DigitalOut led1(LED1);
00041  * DigitalOut led2(LED2);
00042  *
00043  * int flip = 0;
00044  *
00045  * void attime() {
00046  *     flip = !flip;
00047  * }
00048  *
00049  * int main() {
00050  *     timer.attach(&attime, 5);
00051  *     while(1) {
00052  *         if(flip == 0) {
00053  *             led1 = !led1;
00054  *         } else {
00055  *             led2 = !led2;
00056  *         }
00057  *         wait(0.2);
00058  *     }
00059  * }
00060  * @endcode
00061  */
00062 class Ticker : public TimerEvent {
00063 
00064 public:
00065     Ticker() : TimerEvent() {
00066     }
00067 
00068     Ticker(const ticker_data_t *data) : TimerEvent(data) {
00069         data->interface->init();
00070     }
00071 
00072     /** Attach a function to be called by the Ticker, specifiying the interval in seconds
00073      *
00074      *  @param func pointer to the function to be called
00075      *  @param t the time between calls in seconds
00076      */
00077     void attach(Callback<void()> func, float t) {
00078         attach_us(func, t * 1000000.0f);
00079     }
00080 
00081     /** Attach a member function to be called by the Ticker, specifiying the interval in seconds
00082      *
00083      *  @param obj pointer to the object to call the member function on
00084      *  @param method pointer to the member function to be called
00085      *  @param t the time between calls in seconds
00086      *  @deprecated
00087      *      The attach function does not support cv-qualifiers. Replaced by
00088      *      attach(callback(obj, method), t).
00089      */
00090     template<typename T, typename M>
00091     MBED_DEPRECATED_SINCE("mbed-os-5.1",
00092         "The attach function does not support cv-qualifiers. Replaced by "
00093         "attach(callback(obj, method), t).")
00094     void attach(T *obj, M method, float t) {
00095         attach(callback(obj, method), t);
00096     }
00097 
00098     /** Attach a function to be called by the Ticker, specifiying the interval in micro-seconds
00099      *
00100      *  @param fptr pointer to the function to be called
00101      *  @param t the time between calls in micro-seconds
00102      */
00103     void attach_us(Callback<void()> func, timestamp_t t) {
00104         _function.attach(func);
00105         setup(t);
00106     }
00107 
00108     /** Attach a member function to be called by the Ticker, specifiying the interval in micro-seconds
00109      *
00110      *  @param tptr pointer to the object to call the member function on
00111      *  @param mptr pointer to the member function to be called
00112      *  @param t the time between calls in micro-seconds
00113      *  @deprecated
00114      *      The attach_us function does not support cv-qualifiers. Replaced by
00115      *      attach_us(callback(obj, method), t).
00116      */
00117     template<typename T, typename M>
00118     MBED_DEPRECATED_SINCE("mbed-os-5.1",
00119         "The attach_us function does not support cv-qualifiers. Replaced by "
00120         "attach_us(callback(obj, method), t).")
00121     void attach_us(T *obj, M method, timestamp_t t) {
00122         attach_us(Callback<void()>(obj, method), t);
00123     }
00124 
00125     virtual ~Ticker() {
00126         detach();
00127     }
00128 
00129     /** Detach the function
00130      */
00131     void detach();
00132 
00133 protected:
00134     void setup(timestamp_t t);
00135     virtual void handler();
00136 
00137 protected:
00138     timestamp_t         _delay;     /**< Time delay (in microseconds) for re-setting the multi-shot callback. */
00139     Callback<void()>    _function;  /**< Callback. */
00140 };
00141 
00142 } // namespace mbed
00143 
00144 #endif
00145 
00146 /** @}*/