Gan likun / mbed-dev

00

drivers/DigitalIn.h@0:13413ea9a877, 2022-06-12 (annotated)

Committer:
ganlikun
Date:
Sun Jun 12 14:02:44 2022 +0000
Revision:
0:13413ea9a877
00

Who changed what in which revision?

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ganlikun 0:13413ea9a877 1 /* mbed Microcontroller Library
ganlikun 0:13413ea9a877 2 * Copyright (c) 2006-2013 ARM Limited
ganlikun 0:13413ea9a877 3 *
ganlikun 0:13413ea9a877 4 * Licensed under the Apache License, Version 2.0 (the "License");
ganlikun 0:13413ea9a877 5 * you may not use this file except in compliance with the License.
ganlikun 0:13413ea9a877 6 * You may obtain a copy of the License at
ganlikun 0:13413ea9a877 7 *
ganlikun 0:13413ea9a877 8 * http://www.apache.org/licenses/LICENSE-2.0
ganlikun 0:13413ea9a877 9 *
ganlikun 0:13413ea9a877 10 * Unless required by applicable law or agreed to in writing, software
ganlikun 0:13413ea9a877 11 * distributed under the License is distributed on an "AS IS" BASIS,
ganlikun 0:13413ea9a877 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
ganlikun 0:13413ea9a877 13 * See the License for the specific language governing permissions and
ganlikun 0:13413ea9a877 14 * limitations under the License.
ganlikun 0:13413ea9a877 15 */
ganlikun 0:13413ea9a877 16 #ifndef MBED_DIGITALIN_H
ganlikun 0:13413ea9a877 17 #define MBED_DIGITALIN_H
ganlikun 0:13413ea9a877 18
ganlikun 0:13413ea9a877 19 #include "platform/platform.h"
ganlikun 0:13413ea9a877 20
ganlikun 0:13413ea9a877 21 #include "hal/gpio_api.h"
ganlikun 0:13413ea9a877 22 #include "platform/mbed_critical.h"
ganlikun 0:13413ea9a877 23
ganlikun 0:13413ea9a877 24 namespace mbed {
ganlikun 0:13413ea9a877 25 /** \addtogroup drivers */
ganlikun 0:13413ea9a877 26
ganlikun 0:13413ea9a877 27 /** A digital input, used for reading the state of a pin
ganlikun 0:13413ea9a877 28 *
ganlikun 0:13413ea9a877 29 * @note Synchronization level: Interrupt safe
ganlikun 0:13413ea9a877 30 *
ganlikun 0:13413ea9a877 31 * Example:
ganlikun 0:13413ea9a877 32 * @code
ganlikun 0:13413ea9a877 33 * // Flash an LED while a DigitalIn is true
ganlikun 0:13413ea9a877 34 *
ganlikun 0:13413ea9a877 35 * #include "mbed.h"
ganlikun 0:13413ea9a877 36 *
ganlikun 0:13413ea9a877 37 * DigitalIn enable(p5);
ganlikun 0:13413ea9a877 38 * DigitalOut led(LED1);
ganlikun 0:13413ea9a877 39 *
ganlikun 0:13413ea9a877 40 * int main() {
ganlikun 0:13413ea9a877 41 * while(1) {
ganlikun 0:13413ea9a877 42 * if(enable) {
ganlikun 0:13413ea9a877 43 * led = !led;
ganlikun 0:13413ea9a877 44 * }
ganlikun 0:13413ea9a877 45 * wait(0.25);
ganlikun 0:13413ea9a877 46 * }
ganlikun 0:13413ea9a877 47 * }
ganlikun 0:13413ea9a877 48 * @endcode
ganlikun 0:13413ea9a877 49 * @ingroup drivers
ganlikun 0:13413ea9a877 50 */
ganlikun 0:13413ea9a877 51 class DigitalIn {
ganlikun 0:13413ea9a877 52
ganlikun 0:13413ea9a877 53 public:
ganlikun 0:13413ea9a877 54 /** Create a DigitalIn connected to the specified pin
ganlikun 0:13413ea9a877 55 *
ganlikun 0:13413ea9a877 56 * @param pin DigitalIn pin to connect to
ganlikun 0:13413ea9a877 57 */
ganlikun 0:13413ea9a877 58 DigitalIn(PinName pin) : gpio() {
ganlikun 0:13413ea9a877 59 // No lock needed in the constructor
ganlikun 0:13413ea9a877 60 gpio_init_in(&gpio, pin);
ganlikun 0:13413ea9a877 61 }
ganlikun 0:13413ea9a877 62
ganlikun 0:13413ea9a877 63 /** Create a DigitalIn connected to the specified pin
ganlikun 0:13413ea9a877 64 *
ganlikun 0:13413ea9a877 65 * @param pin DigitalIn pin to connect to
ganlikun 0:13413ea9a877 66 * @param mode the initial mode of the pin
ganlikun 0:13413ea9a877 67 */
ganlikun 0:13413ea9a877 68 DigitalIn(PinName pin, PinMode mode) : gpio() {
ganlikun 0:13413ea9a877 69 // No lock needed in the constructor
ganlikun 0:13413ea9a877 70 gpio_init_in_ex(&gpio, pin, mode);
ganlikun 0:13413ea9a877 71 }
ganlikun 0:13413ea9a877 72 /** Read the input, represented as 0 or 1 (int)
ganlikun 0:13413ea9a877 73 *
ganlikun 0:13413ea9a877 74 * @returns
ganlikun 0:13413ea9a877 75 * An integer representing the state of the input pin,
ganlikun 0:13413ea9a877 76 * 0 for logical 0, 1 for logical 1
ganlikun 0:13413ea9a877 77 */
ganlikun 0:13413ea9a877 78 int read() {
ganlikun 0:13413ea9a877 79 // Thread safe / atomic HAL call
ganlikun 0:13413ea9a877 80 return gpio_read(&gpio);
ganlikun 0:13413ea9a877 81 }
ganlikun 0:13413ea9a877 82
ganlikun 0:13413ea9a877 83 /** Set the input pin mode
ganlikun 0:13413ea9a877 84 *
ganlikun 0:13413ea9a877 85 * @param pull PullUp, PullDown, PullNone, OpenDrain
ganlikun 0:13413ea9a877 86 */
ganlikun 0:13413ea9a877 87 void mode(PinMode pull) {
ganlikun 0:13413ea9a877 88 core_util_critical_section_enter();
ganlikun 0:13413ea9a877 89 gpio_mode(&gpio, pull);
ganlikun 0:13413ea9a877 90 core_util_critical_section_exit();
ganlikun 0:13413ea9a877 91 }
ganlikun 0:13413ea9a877 92
ganlikun 0:13413ea9a877 93 /** Return the output setting, represented as 0 or 1 (int)
ganlikun 0:13413ea9a877 94 *
ganlikun 0:13413ea9a877 95 * @returns
ganlikun 0:13413ea9a877 96 * Non zero value if pin is connected to uc GPIO
ganlikun 0:13413ea9a877 97 * 0 if gpio object was initialized with NC
ganlikun 0:13413ea9a877 98 */
ganlikun 0:13413ea9a877 99 int is_connected() {
ganlikun 0:13413ea9a877 100 // Thread safe / atomic HAL call
ganlikun 0:13413ea9a877 101 return gpio_is_connected(&gpio);
ganlikun 0:13413ea9a877 102 }
ganlikun 0:13413ea9a877 103
ganlikun 0:13413ea9a877 104 /** An operator shorthand for read()
ganlikun 0:13413ea9a877 105 * \sa DigitalIn::read()
ganlikun 0:13413ea9a877 106 */
ganlikun 0:13413ea9a877 107 operator int() {
ganlikun 0:13413ea9a877 108 // Underlying read is thread safe
ganlikun 0:13413ea9a877 109 return read();
ganlikun 0:13413ea9a877 110 }
ganlikun 0:13413ea9a877 111
ganlikun 0:13413ea9a877 112 protected:
ganlikun 0:13413ea9a877 113 gpio_t gpio;
ganlikun 0:13413ea9a877 114 };
ganlikun 0:13413ea9a877 115
ganlikun 0:13413ea9a877 116 } // namespace mbed
ganlikun 0:13413ea9a877 117
ganlikun 0:13413ea9a877 118 #endif
ganlikun 0:13413ea9a877 119