InterruptIn.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_INTERRUPTIN_H
00017 #define MBED_INTERRUPTIN_H
00018 
00019 #include "platform.h"
00020 
00021 #if DEVICE_INTERRUPTIN
00022 
00023 #include "gpio_api.h"
00024 #include "gpio_irq_api.h"
00025 #include "Callback.h"
00026 #include "critical.h"
00027 
00028 namespace mbed {
00029 
00030 /** A digital interrupt input, used to call a function on a rising or falling edge
00031  *
00032  * @Note Synchronization level: Interrupt safe
00033  *
00034  * Example:
00035  * @code
00036  * // Flash an LED while waiting for events
00037  *
00038  * #include "mbed.h"
00039  *
00040  * InterruptIn event(p16);
00041  * DigitalOut led(LED1);
00042  *
00043  * void trigger() {
00044  *     printf("triggered!\n");
00045  * }
00046  *
00047  * int main() {
00048  *     event.rise(&trigger);
00049  *     while(1) {
00050  *         led = !led;
00051  *         wait(0.25);
00052  *     }
00053  * }
00054  * @endcode
00055  */
00056 class InterruptIn {
00057 
00058 public:
00059 
00060     /** Create an InterruptIn connected to the specified pin
00061      *
00062      *  @param pin InterruptIn pin to connect to
00063      *  @param name (optional) A string to identify the object
00064      */
00065     InterruptIn(PinName pin);
00066     virtual ~InterruptIn();
00067 
00068     /** Read the input, represented as 0 or 1 (int)
00069      *
00070      *  @returns
00071      *    An integer representing the state of the input pin,
00072      *    0 for logical 0, 1 for logical 1
00073      */
00074     int read();
00075 
00076     /** An operator shorthand for read()
00077      */
00078     operator int();
00079 
00080 
00081     /** Attach a function to call when a rising edge occurs on the input
00082      *
00083      *  @param func A pointer to a void function, or 0 to set as none
00084      */
00085     void rise(Callback<void()> func);
00086 
00087     /** Attach a member function to call when a rising edge occurs on the input
00088      *
00089      *  @param obj pointer to the object to call the member function on
00090      *  @param method pointer to the member function to be called
00091      */
00092     template<typename T, typename M>
00093     void rise(T *obj, M method) {
00094         core_util_critical_section_enter();
00095         rise(Callback<void()>(obj, method));
00096         core_util_critical_section_exit();
00097     }
00098 
00099     /** Attach a function to call when a falling edge occurs on the input
00100      *
00101      *  @param func A pointer to a void function, or 0 to set as none
00102      */
00103     void fall(Callback<void()> func);
00104 
00105     /** Attach a member function to call when a falling edge occurs on the input
00106      *
00107      *  @param obj pointer to the object to call the member function on
00108      *  @param method pointer to the member function to be called
00109      */
00110     template<typename T, typename M>
00111     void fall(T *obj, M method) {
00112         core_util_critical_section_enter();
00113         fall(Callback<void()>(obj, method));
00114         core_util_critical_section_exit();
00115     }
00116 
00117     /** Set the input pin mode
00118      *
00119      *  @param mode PullUp, PullDown, PullNone
00120      */
00121     void mode(PinMode pull);
00122 
00123     /** Enable IRQ. This method depends on hw implementation, might enable one
00124      *  port interrupts. For further information, check gpio_irq_enable().
00125      */
00126     void enable_irq();
00127 
00128     /** Disable IRQ. This method depends on hw implementation, might disable one
00129      *  port interrupts. For further information, check gpio_irq_disable().
00130      */
00131     void disable_irq();
00132 
00133     static void _irq_handler(uint32_t id, gpio_irq_event event);
00134 
00135 protected:
00136     gpio_t gpio;
00137     gpio_irq_t gpio_irq;
00138 
00139     Callback<void()> _rise;
00140     Callback<void()> _fall;
00141 };
00142 
00143 } // namespace mbed
00144 
00145 #endif
00146 
00147 #endif