DigitalInOut.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_DIGITALINOUT_H
00017 #define MBED_DIGITALINOUT_H
00018 
00019 #include "platform.h"
00020 
00021 #include "gpio_api.h"
00022 
00023 namespace mbed {
00024 
00025 /** A digital input/output, used for setting or reading a bi-directional pin
00026  */
00027 class DigitalInOut {
00028 
00029 public:
00030     /** Create a DigitalInOut connected to the specified pin
00031      *
00032      *  @param pin DigitalInOut pin to connect to
00033      */
00034     DigitalInOut(PinName pin) {
00035         gpio_init_in(&gpio, pin);
00036     }
00037 
00038     /** Create a DigitalInOut connected to the specified pin
00039      *
00040      *  @param pin DigitalInOut pin to connect to
00041      *  @param direction the initial direction of the pin
00042      *  @param mode the initial mode of the pin
00043      *  @param value the initial value of the pin if is an output
00044      */
00045     DigitalInOut(PinName pin, PinDirection direction, PinMode mode, int value) {
00046         gpio_init_inout(&gpio, pin, direction, mode, value);
00047     }
00048 
00049     /** Set the output, specified as 0 or 1 (int)
00050      *
00051      *  @param value An integer specifying the pin output value,
00052      *      0 for logical 0, 1 (or any other non-zero value) for logical 1
00053      */
00054     void write(int value) {
00055         gpio_write(&gpio, value);
00056     }
00057 
00058     /** Return the output setting, represented as 0 or 1 (int)
00059      *
00060      *  @returns
00061      *    an integer representing the output setting of the pin if it is an output,
00062      *    or read the input if set as an input
00063      */
00064     int read() {
00065         return gpio_read(&gpio);
00066     }
00067 
00068     /** Set as an output
00069      */
00070     void output() {
00071         gpio_dir(&gpio, PIN_OUTPUT);
00072     }
00073 
00074     /** Set as an input
00075      */
00076     void input() {
00077         gpio_dir(&gpio, PIN_INPUT);
00078     }
00079 
00080     /** Set the input pin mode
00081      *
00082      *  @param mode PullUp, PullDown, PullNone, OpenDrain
00083      */
00084     void mode(PinMode pull) {
00085         gpio_mode(&gpio, pull);
00086     }
00087 
00088 #ifdef MBED_OPERATORS
00089     /** A shorthand for write()
00090      */
00091     DigitalInOut& operator= (int value) {
00092         write(value);
00093         return *this;
00094     }
00095 
00096     DigitalInOut& operator= (DigitalInOut& rhs) {
00097         write(rhs.read());
00098         return *this;
00099     }
00100 
00101     /** A shorthand for read()
00102      */
00103     operator int() {
00104         return read();
00105     }
00106 #endif
00107 
00108 protected:
00109     gpio_t gpio;
00110 };
00111 
00112 } // namespace mbed
00113 
00114 #endif