Lee Kai Xuan / mbed-os

mbed-os

Fork of mbed-os by erkin yucel

drivers/DigitalIn.h@0:f269e3021894, 2016-10-23 (annotated)

Committer:
elessair
Date:
Sun Oct 23 15:10:02 2016 +0000
Revision:
0:f269e3021894
Initial commit

Who changed what in which revision?

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elessair 0:f269e3021894 1 /* mbed Microcontroller Library
elessair 0:f269e3021894 2 * Copyright (c) 2006-2013 ARM Limited
elessair 0:f269e3021894 3 *
elessair 0:f269e3021894 4 * Licensed under the Apache License, Version 2.0 (the "License");
elessair 0:f269e3021894 5 * you may not use this file except in compliance with the License.
elessair 0:f269e3021894 6 * You may obtain a copy of the License at
elessair 0:f269e3021894 7 *
elessair 0:f269e3021894 8 * http://www.apache.org/licenses/LICENSE-2.0
elessair 0:f269e3021894 9 *
elessair 0:f269e3021894 10 * Unless required by applicable law or agreed to in writing, software
elessair 0:f269e3021894 11 * distributed under the License is distributed on an "AS IS" BASIS,
elessair 0:f269e3021894 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
elessair 0:f269e3021894 13 * See the License for the specific language governing permissions and
elessair 0:f269e3021894 14 * limitations under the License.
elessair 0:f269e3021894 15 */
elessair 0:f269e3021894 16 #ifndef MBED_DIGITALIN_H
elessair 0:f269e3021894 17 #define MBED_DIGITALIN_H
elessair 0:f269e3021894 18
elessair 0:f269e3021894 19 #include "platform/platform.h"
elessair 0:f269e3021894 20
elessair 0:f269e3021894 21 #include "hal/gpio_api.h"
elessair 0:f269e3021894 22 #include "platform/critical.h"
elessair 0:f269e3021894 23
elessair 0:f269e3021894 24 namespace mbed {
elessair 0:f269e3021894 25 /** \addtogroup drivers */
elessair 0:f269e3021894 26 /** @{*/
elessair 0:f269e3021894 27
elessair 0:f269e3021894 28 /** A digital input, used for reading the state of a pin
elessair 0:f269e3021894 29 *
elessair 0:f269e3021894 30 * @Note Synchronization level: Interrupt safe
elessair 0:f269e3021894 31 *
elessair 0:f269e3021894 32 * Example:
elessair 0:f269e3021894 33 * @code
elessair 0:f269e3021894 34 * // Flash an LED while a DigitalIn is true
elessair 0:f269e3021894 35 *
elessair 0:f269e3021894 36 * #include "mbed.h"
elessair 0:f269e3021894 37 *
elessair 0:f269e3021894 38 * DigitalIn enable(p5);
elessair 0:f269e3021894 39 * DigitalOut led(LED1);
elessair 0:f269e3021894 40 *
elessair 0:f269e3021894 41 * int main() {
elessair 0:f269e3021894 42 * while(1) {
elessair 0:f269e3021894 43 * if(enable) {
elessair 0:f269e3021894 44 * led = !led;
elessair 0:f269e3021894 45 * }
elessair 0:f269e3021894 46 * wait(0.25);
elessair 0:f269e3021894 47 * }
elessair 0:f269e3021894 48 * }
elessair 0:f269e3021894 49 * @endcode
elessair 0:f269e3021894 50 */
elessair 0:f269e3021894 51 class DigitalIn {
elessair 0:f269e3021894 52
elessair 0:f269e3021894 53 public:
elessair 0:f269e3021894 54 /** Create a DigitalIn connected to the specified pin
elessair 0:f269e3021894 55 *
elessair 0:f269e3021894 56 * @param pin DigitalIn pin to connect to
elessair 0:f269e3021894 57 */
elessair 0:f269e3021894 58 DigitalIn(PinName pin) : gpio() {
elessair 0:f269e3021894 59 // No lock needed in the constructor
elessair 0:f269e3021894 60 gpio_init_in(&gpio, pin);
elessair 0:f269e3021894 61 }
elessair 0:f269e3021894 62
elessair 0:f269e3021894 63 /** Create a DigitalIn connected to the specified pin
elessair 0:f269e3021894 64 *
elessair 0:f269e3021894 65 * @param pin DigitalIn pin to connect to
elessair 0:f269e3021894 66 * @param mode the initial mode of the pin
elessair 0:f269e3021894 67 */
elessair 0:f269e3021894 68 DigitalIn(PinName pin, PinMode mode) : gpio() {
elessair 0:f269e3021894 69 // No lock needed in the constructor
elessair 0:f269e3021894 70 gpio_init_in_ex(&gpio, pin, mode);
elessair 0:f269e3021894 71 }
elessair 0:f269e3021894 72 /** Read the input, represented as 0 or 1 (int)
elessair 0:f269e3021894 73 *
elessair 0:f269e3021894 74 * @returns
elessair 0:f269e3021894 75 * An integer representing the state of the input pin,
elessair 0:f269e3021894 76 * 0 for logical 0, 1 for logical 1
elessair 0:f269e3021894 77 */
elessair 0:f269e3021894 78 int read() {
elessair 0:f269e3021894 79 // Thread safe / atomic HAL call
elessair 0:f269e3021894 80 return gpio_read(&gpio);
elessair 0:f269e3021894 81 }
elessair 0:f269e3021894 82
elessair 0:f269e3021894 83 /** Set the input pin mode
elessair 0:f269e3021894 84 *
elessair 0:f269e3021894 85 * @param mode PullUp, PullDown, PullNone, OpenDrain
elessair 0:f269e3021894 86 */
elessair 0:f269e3021894 87 void mode(PinMode pull) {
elessair 0:f269e3021894 88 core_util_critical_section_enter();
elessair 0:f269e3021894 89 gpio_mode(&gpio, pull);
elessair 0:f269e3021894 90 core_util_critical_section_exit();
elessair 0:f269e3021894 91 }
elessair 0:f269e3021894 92
elessair 0:f269e3021894 93 /** Return the output setting, represented as 0 or 1 (int)
elessair 0:f269e3021894 94 *
elessair 0:f269e3021894 95 * @returns
elessair 0:f269e3021894 96 * Non zero value if pin is connected to uc GPIO
elessair 0:f269e3021894 97 * 0 if gpio object was initialized with NC
elessair 0:f269e3021894 98 */
elessair 0:f269e3021894 99 int is_connected() {
elessair 0:f269e3021894 100 // Thread safe / atomic HAL call
elessair 0:f269e3021894 101 return gpio_is_connected(&gpio);
elessair 0:f269e3021894 102 }
elessair 0:f269e3021894 103
elessair 0:f269e3021894 104 /** An operator shorthand for read()
elessair 0:f269e3021894 105 */
elessair 0:f269e3021894 106 operator int() {
elessair 0:f269e3021894 107 // Underlying read is thread safe
elessair 0:f269e3021894 108 return read();
elessair 0:f269e3021894 109 }
elessair 0:f269e3021894 110
elessair 0:f269e3021894 111 protected:
elessair 0:f269e3021894 112 gpio_t gpio;
elessair 0:f269e3021894 113 };
elessair 0:f269e3021894 114
elessair 0:f269e3021894 115 } // namespace mbed
elessair 0:f269e3021894 116
elessair 0:f269e3021894 117 #endif
elessair 0:f269e3021894 118
elessair 0:f269e3021894 119 /** @}*/