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/* mbed Microcontroller Library
* Copyright (c) 2006-2013 ARM Limited
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef MBED_ANALOGIN_H
#define MBED_ANALOGIN_H
#include "platform/platform.h"
#if DEVICE_ANALOGIN
#include "hal/analogin_api.h"
#include "platform/SingletonPtr.h"
#include "platform/PlatformMutex.h"
namespace mbed {
/** \addtogroup drivers */
/** @{*/
/** An analog input, used for reading the voltage on a pin
*
* @Note Synchronization level: Thread safe
*
* Example:
* @code
* // Print messages when the AnalogIn is greater than 50%
*
* #include "mbed.h"
*
* AnalogIn temperature(p20);
*
* int main() {
* while(1) {
* if(temperature > 0.5) {
* printf("Too hot! (%f)", temperature.read());
* }
* }
* }
* @endcode
*/
class AnalogIn {
public:
/** Create an AnalogIn, connected to the specified pin
*
* @param pin AnalogIn pin to connect to
* @param name (optional) A string to identify the object
*/
AnalogIn(PinName pin) {
lock();
analogin_init(&_adc, pin);
unlock();
}
/** Read the input voltage, represented as a float in the range [0.0, 1.0]
*
* @returns A floating-point value representing the current input voltage, measured as a percentage
*/
float read() {
lock();
float ret = analogin_read(&_adc);
unlock();
return ret;
}
/** Read the input voltage, represented as an unsigned short in the range [0x0, 0xFFFF]
*
* @returns
* 16-bit unsigned short representing the current input voltage, normalised to a 16-bit value
*/
unsigned short read_u16() {
lock();
unsigned short ret = analogin_read_u16(&_adc);
unlock();
return ret;
}
/** An operator shorthand for read()
*
* The float() operator can be used as a shorthand for read() to simplify common code sequences
*
* Example:
* @code
* float x = volume.read();
* float x = volume;
*
* if(volume.read() > 0.25) { ... }
* if(volume > 0.25) { ... }
* @endcode
*/
operator float() {
// Underlying call is thread safe
return read();
}
virtual ~AnalogIn() {
// Do nothing
}
protected:
virtual void lock() {
_mutex->lock();
}
virtual void unlock() {
_mutex->unlock();
}
analogin_t _adc;
static SingletonPtr<PlatformMutex> _mutex;
};
} // namespace mbed
#endif
#endif
/** @}*/
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