siva surendar / mbed-dev

mbed library sources. Supersedes mbed-src.

Fork of mbed-dev by mbed official

drivers/AnalogIn.h@150:da61ba4e9755, 2016-11-25 (annotated)

Committer:
sivasuren
Date:
Fri Nov 25 07:57:40 2016 +0000
Revision:
150:da61ba4e9755
Parent:
149:156823d33999 
surendar changes

Who changed what in which revision?

UserRevisionLine numberNew contents of line
<> 149:156823d33999 1 /* mbed Microcontroller Library
<> 149:156823d33999 2 * Copyright (c) 2006-2013 ARM Limited
<> 149:156823d33999 3 *
<> 149:156823d33999 4 * Licensed under the Apache License, Version 2.0 (the "License");
<> 149:156823d33999 5 * you may not use this file except in compliance with the License.
<> 149:156823d33999 6 * You may obtain a copy of the License at
<> 149:156823d33999 7 *
<> 149:156823d33999 8 * http://www.apache.org/licenses/LICENSE-2.0
<> 149:156823d33999 9 *
<> 149:156823d33999 10 * Unless required by applicable law or agreed to in writing, software
<> 149:156823d33999 11 * distributed under the License is distributed on an "AS IS" BASIS,
<> 149:156823d33999 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
<> 149:156823d33999 13 * See the License for the specific language governing permissions and
<> 149:156823d33999 14 * limitations under the License.
<> 149:156823d33999 15 */
<> 149:156823d33999 16 #ifndef MBED_ANALOGIN_H
<> 149:156823d33999 17 #define MBED_ANALOGIN_H
<> 149:156823d33999 18
<> 149:156823d33999 19 #include "platform/platform.h"
<> 149:156823d33999 20
<> 149:156823d33999 21 #if DEVICE_ANALOGIN
<> 149:156823d33999 22
<> 149:156823d33999 23 #include "hal/analogin_api.h"
<> 149:156823d33999 24 #include "platform/SingletonPtr.h"
<> 149:156823d33999 25 #include "platform/PlatformMutex.h"
<> 149:156823d33999 26
<> 149:156823d33999 27 namespace mbed {
<> 149:156823d33999 28 /** \addtogroup drivers */
<> 149:156823d33999 29 /** @{*/
<> 149:156823d33999 30
<> 149:156823d33999 31 /** An analog input, used for reading the voltage on a pin
<> 149:156823d33999 32 *
<> 149:156823d33999 33 * @Note Synchronization level: Thread safe
<> 149:156823d33999 34 *
<> 149:156823d33999 35 * Example:
<> 149:156823d33999 36 * @code
<> 149:156823d33999 37 * // Print messages when the AnalogIn is greater than 50%
<> 149:156823d33999 38 *
<> 149:156823d33999 39 * #include "mbed.h"
<> 149:156823d33999 40 *
<> 149:156823d33999 41 * AnalogIn temperature(p20);
<> 149:156823d33999 42 *
<> 149:156823d33999 43 * int main() {
<> 149:156823d33999 44 * while(1) {
<> 149:156823d33999 45 * if(temperature > 0.5) {
<> 149:156823d33999 46 * printf("Too hot! (%f)", temperature.read());
<> 149:156823d33999 47 * }
<> 149:156823d33999 48 * }
<> 149:156823d33999 49 * }
<> 149:156823d33999 50 * @endcode
<> 149:156823d33999 51 */
<> 149:156823d33999 52 class AnalogIn {
<> 149:156823d33999 53
<> 149:156823d33999 54 public:
<> 149:156823d33999 55
<> 149:156823d33999 56 /** Create an AnalogIn, connected to the specified pin
<> 149:156823d33999 57 *
<> 149:156823d33999 58 * @param pin AnalogIn pin to connect to
<> 149:156823d33999 59 * @param name (optional) A string to identify the object
<> 149:156823d33999 60 */
<> 149:156823d33999 61 AnalogIn(PinName pin) {
<> 149:156823d33999 62 lock();
<> 149:156823d33999 63 analogin_init(&_adc, pin);
<> 149:156823d33999 64 unlock();
<> 149:156823d33999 65 }
<> 149:156823d33999 66
<> 149:156823d33999 67 /** Read the input voltage, represented as a float in the range [0.0, 1.0]
<> 149:156823d33999 68 *
<> 149:156823d33999 69 * @returns A floating-point value representing the current input voltage, measured as a percentage
<> 149:156823d33999 70 */
<> 149:156823d33999 71 float read() {
<> 149:156823d33999 72 lock();
<> 149:156823d33999 73 float ret = analogin_read(&_adc);
<> 149:156823d33999 74 unlock();
<> 149:156823d33999 75 return ret;
<> 149:156823d33999 76 }
<> 149:156823d33999 77
<> 149:156823d33999 78 /** Read the input voltage, represented as an unsigned short in the range [0x0, 0xFFFF]
<> 149:156823d33999 79 *
<> 149:156823d33999 80 * @returns
<> 149:156823d33999 81 * 16-bit unsigned short representing the current input voltage, normalised to a 16-bit value
<> 149:156823d33999 82 */
<> 149:156823d33999 83 unsigned short read_u16() {
<> 149:156823d33999 84 lock();
<> 149:156823d33999 85 unsigned short ret = analogin_read_u16(&_adc);
<> 149:156823d33999 86 unlock();
<> 149:156823d33999 87 return ret;
<> 149:156823d33999 88 }
<> 149:156823d33999 89
<> 149:156823d33999 90 /** An operator shorthand for read()
<> 149:156823d33999 91 *
<> 149:156823d33999 92 * The float() operator can be used as a shorthand for read() to simplify common code sequences
<> 149:156823d33999 93 *
<> 149:156823d33999 94 * Example:
<> 149:156823d33999 95 * @code
<> 149:156823d33999 96 * float x = volume.read();
<> 149:156823d33999 97 * float x = volume;
<> 149:156823d33999 98 *
<> 149:156823d33999 99 * if(volume.read() > 0.25) { ... }
<> 149:156823d33999 100 * if(volume > 0.25) { ... }
<> 149:156823d33999 101 * @endcode
<> 149:156823d33999 102 */
<> 149:156823d33999 103 operator float() {
<> 149:156823d33999 104 // Underlying call is thread safe
<> 149:156823d33999 105 return read();
<> 149:156823d33999 106 }
<> 149:156823d33999 107
<> 149:156823d33999 108 virtual ~AnalogIn() {
<> 149:156823d33999 109 // Do nothing
<> 149:156823d33999 110 }
<> 149:156823d33999 111
<> 149:156823d33999 112 protected:
<> 149:156823d33999 113
<> 149:156823d33999 114 virtual void lock() {
<> 149:156823d33999 115 _mutex->lock();
<> 149:156823d33999 116 }
<> 149:156823d33999 117
<> 149:156823d33999 118 virtual void unlock() {
<> 149:156823d33999 119 _mutex->unlock();
<> 149:156823d33999 120 }
<> 149:156823d33999 121
<> 149:156823d33999 122 analogin_t _adc;
<> 149:156823d33999 123 static SingletonPtr<PlatformMutex> _mutex;
<> 149:156823d33999 124 };
<> 149:156823d33999 125
<> 149:156823d33999 126 } // namespace mbed
<> 149:156823d33999 127
<> 149:156823d33999 128 #endif
<> 149:156823d33999 129
<> 149:156823d33999 130 #endif
<> 149:156823d33999 131
<> 149:156823d33999 132 /** @}*/