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AnalogIn.h
1 /* mbed Microcontroller Library
2  * Copyright (c) 2006-2019 ARM Limited
3  * SPDX-License-Identifier: Apache-2.0
4  *
5  * Licensed under the Apache License, Version 2.0 (the "License");
6  * you may not use this file except in compliance with the License.
7  * You may obtain a copy of the License at
8  *
9  * http://www.apache.org/licenses/LICENSE-2.0
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  */
17 #ifndef MBED_ANALOGIN_H
18 #define MBED_ANALOGIN_H
19 
20 #include "platform/platform.h"
21 
22 #if DEVICE_ANALOGIN || defined(DOXYGEN_ONLY)
23 
24 #include "hal/analogin_api.h"
25 #include "platform/SingletonPtr.h"
26 #include "platform/PlatformMutex.h"
27 
28 namespace mbed {
29 /** \defgroup mbed-os-public Public API */
30 
31 /** \defgroup drivers-public-api Drivers
32  * \ingroup mbed-os-public
33  */
34 
35 /** \defgroup drivers-public-api-gpio GPIO
36  * \ingroup drivers-public-api
37  */
38 
39 /**
40  * \defgroup drivers_AnalogIn AnalogIn class
41  * \ingroup drivers-public-api-gpio
42  * @{
43  */
44 
45 /** An analog input, used for reading the voltage on a pin
46  *
47  * @note Synchronization level: Thread safe
48  *
49  * Example:
50  * @code
51  * // Print messages when the AnalogIn is greater than 50%
52  *
53  * #include "mbed.h"
54  *
55  * AnalogIn temperature(p20);
56  *
57  * int main() {
58  * while(1) {
59  * if(temperature > 0.5) {
60  * printf("Too hot! (%f)", temperature.read());
61  * }
62  * }
63  * }
64  * @endcode
65  */
66 class AnalogIn {
67 
68 public:
69 
70  /** Create an AnalogIn, connected to the specified pin
71  *
72  * @param pinmap reference to structure which holds static pinmap.
73  */
74  AnalogIn(const PinMap &pinmap);
75  AnalogIn(const PinMap &&) = delete; // prevent passing of temporary objects
76 
77  /** Create an AnalogIn, connected to the specified pin
78  *
79  * @param pin AnalogIn pin to connect to
80  */
81  AnalogIn(PinName pin);
82 
83  /** Read the input voltage, represented as a float in the range [0.0, 1.0]
84  *
85  * @returns A floating-point value representing the current input voltage, measured as a percentage
86  */
87  float read();
88 
89  /** Read the input voltage, represented as an unsigned short in the range [0x0, 0xFFFF]
90  *
91  * @returns
92  * 16-bit unsigned short representing the current input voltage, normalized to a 16-bit value
93  */
94  unsigned short read_u16();
95 
96  /** An operator shorthand for read()
97  *
98  * The float() operator can be used as a shorthand for read() to simplify common code sequences
99  *
100  * Example:
101  * @code
102  * float x = volume.read();
103  * float x = volume;
104  *
105  * if(volume.read() > 0.25) { ... }
106  * if(volume > 0.25) { ... }
107  * @endcode
108  */
109  operator float()
110  {
111  // Underlying call is thread safe
112  return read();
113  }
114 
115  virtual ~AnalogIn()
116  {
117  // Do nothing
118  }
119 
120 protected:
121 #if !defined(DOXYGEN_ONLY)
122  virtual void lock()
123  {
124  _mutex->lock();
125  }
126 
127  virtual void unlock()
128  {
129  _mutex->unlock();
130  }
131 
132  analogin_t _adc;
133  static SingletonPtr<PlatformMutex> _mutex;
134 #endif //!defined(DOXYGEN_ONLY)
135 
136 };
137 
138 /** @}*/
139 
140 } // namespace mbed
141 
142 #endif
143 
144 #endif
analogin_t
struct analogin_s analogin_t
Analogin hal structure.
Definition: analogin_api.h:34
mbed::AnalogIn::AnalogIn
AnalogIn(const PinMap &pinmap)
Create an AnalogIn, connected to the specified pin.
mbed::AnalogIn
An analog input, used for reading the voltage on a pin.
Definition: AnalogIn.h:66
mbed::AnalogIn::read
float read()
Read the input voltage, represented as a float in the range [0.0, 1.0].
mbed::AnalogIn::read_u16
unsigned short read_u16()
Read the input voltage, represented as an unsigned short in the range [0x0, 0xFFFF].
PinMap
Definition: pinmap.h:31
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