File content as of revision 54:71b101360fb9:

/* mbed Microcontroller Library
 * Copyright (c) 2006-2013 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_ANALOGOUT_H
#define MBED_ANALOGOUT_H

#include "platform.h"

#if DEVICE_ANALOGOUT

#include "analogout_api.h"

namespace mbed {

/** An analog output, used for setting the voltage on a pin
 *
 * Example:
 * @code
 * // Make a sawtooth output
 *  
 * #include "mbed.h"
 *  
 * AnalogOut tri(p18);
 * int main() {
 *     while(1) {
 *         tri = tri + 0.01;
 *         wait_us(1);
 *         if(tri == 1) {
 *             tri = 0;
 *         }
 *     }
 * }
 * @endcode
 */
class AnalogOut {

public:

    /** Create an AnalogOut connected to the specified pin
     * 
     *  @param AnalogOut pin to connect to (18)
     */
    AnalogOut(PinName pin) {
        analogout_init(&_dac, pin);
    }
    
    /** Set the output voltage, specified as a percentage (float)
     *
     *  @param value A floating-point value representing the output voltage, 
     *    specified as a percentage. The value should lie between
     *    0.0f (representing 0v / 0%) and 1.0f (representing 3.3v / 100%).
     *    Values outside this range will be saturated to 0.0f or 1.0f.
     */
    void write(float value) {
        analogout_write(&_dac, value);
    }
    
    /** Set the output voltage, represented as an unsigned short in the range [0x0, 0xFFFF]
     *
     *  @param value 16-bit unsigned short representing the output voltage,
     *            normalised to a 16-bit value (0x0000 = 0v, 0xFFFF = 3.3v)
     */
    void write_u16(unsigned short value) {
        analogout_write_u16(&_dac, value);
    }

    /** Return the current output voltage setting, measured as a percentage (float)
     *
     *  @returns
     *    A floating-point value representing the current voltage being output on the pin, 
     *    measured as a percentage. The returned value will lie between
     *    0.0f (representing 0v / 0%) and 1.0f (representing 3.3v / 100%).
     *
     *  @note
     *    This value may not match exactly the value set by a previous write().
     */
    float read() {
        return analogout_read(&_dac);
    }

#ifdef MBED_OPERATORS
    /** An operator shorthand for write()
     */
    AnalogOut& operator= (float percent) {
        write(percent);
        return *this;
    }
    
    AnalogOut& operator= (AnalogOut& rhs) {
        write(rhs.read());
        return *this;
    }

    /** An operator shorthand for read()
     */
    operator float() {
        return read();
    }
#endif

protected:
    dac_t _dac;
};

} // namespace mbed

#endif

#endif