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