Timer.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_TIMER_H
00017 #define MBED_TIMER_H
00018 
00019 #include "platform.h"
00020 #include "ticker_api.h"
00021 
00022 namespace mbed {
00023 
00024 /** A general purpose timer
00025  *
00026  * Example:
00027  * @code
00028  * // Count the time to toggle a LED
00029  *
00030  * #include "mbed.h"
00031  *
00032  * Timer timer;
00033  * DigitalOut led(LED1);
00034  * int begin, end;
00035  *
00036  * int main() {
00037  *     timer.start();
00038  *     begin = timer.read_us();
00039  *     led = !led;
00040  *     end = timer.read_us();
00041  *     printf("Toggle the led takes %d us", end - begin);
00042  * }
00043  * @endcode
00044  */
00045 class Timer {
00046 
00047 public:
00048     Timer();
00049     Timer(const ticker_data_t *data);
00050 
00051     /** Start the timer
00052      */
00053     void start();
00054 
00055     /** Stop the timer
00056      */
00057     void stop();
00058 
00059     /** Reset the timer to 0.
00060      *
00061      * If it was already counting, it will continue
00062      */
00063     void reset();
00064 
00065     /** Get the time passed in seconds
00066      */
00067     float read();
00068 
00069     /** Get the time passed in mili-seconds
00070      */
00071     int read_ms();
00072 
00073     /** Get the time passed in micro-seconds
00074      */
00075     int read_us();
00076 
00077 #ifdef MBED_OPERATORS
00078     operator float();
00079 #endif
00080 
00081 protected:
00082     int slicetime();
00083     int _running;          // whether the timer is running
00084     unsigned int _start;   // the start time of the latest slice
00085     int _time;             // any accumulated time from previous slices
00086     const ticker_data_t *_ticker_data;
00087 };
00088 
00089 } // namespace mbed
00090 
00091 #endif