tmk_core/tool/mbed/mbed-sdk/libraries/mbed/api/DigitalIn.h

   1 /* mbed Microcontroller Library
   2  * Copyright (c) 2006-2013 ARM Limited
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 #ifndef MBED_DIGITALIN_H
  17 #define MBED_DIGITALIN_H
  18
  19 #include "platform.h"
  20
  21 #include "gpio_api.h"
  22
  23 namespace mbed {
  24
  25 /** A digital input, used for reading the state of a pin
  26  *
  27  * Example:
  28  * @code
  29  * // Flash an LED while a DigitalIn is true
  30  *
  31  * #include "mbed.h"
  32  *
  33  * DigitalIn enable(p5);
  34  * DigitalOut led(LED1);
  35  *
  36  * int main() {
  37  *     while(1) {
  38  *         if(enable) {
  39  *             led = !led;
  40  *         }
  41  *         wait(0.25);
  42  *     }
  43  * }
  44  * @endcode
  45  */
  46 class DigitalIn {
  47
  48 public:
  49     /** Create a DigitalIn connected to the specified pin
  50      *
  51      *  @param pin DigitalIn pin to connect to
  52      */
  53     DigitalIn(PinName pin) : gpio() {
  54         gpio_init_in(&gpio, pin);
  55     }
  56
  57     /** Create a DigitalIn connected to the specified pin
  58      *
  59      *  @param pin DigitalIn pin to connect to
  60      *  @param mode the initial mode of the pin
  61      */
  62     DigitalIn(PinName pin, PinMode mode) : gpio() {
  63         gpio_init_in_ex(&gpio, pin, mode);
  64     }
  65     /** Read the input, represented as 0 or 1 (int)
  66      *
  67      *  @returns
  68      *    An integer representing the state of the input pin,
  69      *    0 for logical 0, 1 for logical 1
  70      */
  71     int read() {
  72         return gpio_read(&gpio);
  73     }
  74
  75     /** Set the input pin mode
  76      *
  77      *  @param mode PullUp, PullDown, PullNone, OpenDrain
  78      */
  79     void mode(PinMode pull) {
  80         gpio_mode(&gpio, pull);
  81     }
  82
  83     /** Return the output setting, represented as 0 or 1 (int)
  84      *
  85      *  @returns
  86      *    Non zero value if pin is connected to uc GPIO
  87      *    0 if gpio object was initialized with NC
  88      */
  89     int is_connected() {
  90         return gpio_is_connected(&gpio);
  91     }
  92
  93 #ifdef MBED_OPERATORS
  94     /** An operator shorthand for read()
  95      */
  96     operator int() {
  97         return read();
  98     }
  99 #endif
 100
 101 protected:
 102     gpio_t gpio;
 103 };
 104
 105 } // namespace mbed
 106
 107 #endif