File content as of revision 0:fd0d7bdfcdc2:

/* mbed Microcontroller Library
 * Copyright (c) 2006-2012 ARM Limited
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
#ifndef MBED_ANALOGIN_H
#define MBED_ANALOGIN_H

#include "platform.h"

#if DEVICE_ANALOGIN

#include "analogin_api.h"

namespace mbed {

/** An analog input, used for reading the voltage on a pin
 *
 * 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) {
        analogin_init(&_adc, pin);
    }
    
    /** 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() {
        return analogin_read(&_adc);
    }

    /** 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() {
        return analogin_read_u16(&_adc);
    }

#ifdef MBED_OPERATORS
    /** 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() {
        return read();
    }
#endif

protected:
    analogin_t _adc;
};

} // namespace mbed

#endif

#endif