DigitalIn.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_DIGITALIN_H
00017 #define MBED_DIGITALIN_H
00018 
00019 #include "platform.h"
00020 
00021 #include "gpio_api.h"
00022 
00023 namespace mbed {
00024 
00025 /** A digital input, used for reading the state of a pin
00026  *
00027  * Example:
00028  * @code
00029  * // Flash an LED while a DigitalIn is true
00030  *
00031  * #include "mbed.h"
00032  *
00033  * DigitalIn enable(p5);
00034  * DigitalOut led(LED1);
00035  *
00036  * int main() {
00037  *     while(1) {
00038  *         if(enable) {
00039  *             led = !led;
00040  *         }
00041  *         wait(0.25);
00042  *     }
00043  * }
00044  * @endcode
00045  */
00046 class DigitalIn {
00047 
00048 public:
00049     /** Create a DigitalIn connected to the specified pin
00050      *
00051      *  @param pin DigitalIn pin to connect to
00052      *  @param name (optional) A string to identify the object
00053      */
00054     DigitalIn(PinName pin) {
00055         gpio_init(&gpio, pin, PIN_INPUT);
00056     }
00057 
00058     /** Read the input, represented as 0 or 1 (int)
00059      *
00060      *  @returns
00061      *    An integer representing the state of the input pin,
00062      *    0 for logical 0, 1 for logical 1
00063      */
00064     int read() {
00065         return gpio_read(&gpio);
00066     }
00067 
00068     /** Set the input pin mode
00069      *
00070      *  @param mode PullUp, PullDown, PullNone, OpenDrain
00071      */
00072     void mode(PinMode pull) {
00073         gpio_mode(&gpio, pull);
00074     }
00075 
00076 #ifdef MBED_OPERATORS
00077     /** An operator shorthand for read()
00078      */
00079     operator int() {
00080         return read();
00081     }
00082 #endif
00083 
00084 protected:
00085     gpio_t gpio;
00086 };
00087 
00088 } // namespace mbed
00089 
00090 #endif