mbed library sources
Dependents: frdm_kl05z_gpio_test
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Diff: cpp/PwmOut.h
- Revision:
- 0:fd0d7bdfcdc2
- Child:
- 2:143cac498751
diff -r 000000000000 -r fd0d7bdfcdc2 cpp/PwmOut.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/cpp/PwmOut.h Tue Nov 20 17:24:08 2012 +0000 @@ -0,0 +1,164 @@ +/* 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_PWMOUT_H +#define MBED_PWMOUT_H + +#include "platform.h" + +#if DEVICE_PWMOUT +#include "pwmout_api.h" + +namespace mbed { + +/** A pulse-width modulation digital output + * + * Example + * @code + * // Fade a led on. + * #include "mbed.h" + * + * PwmOut led(LED1); + * + * int main() { + * while(1) { + * led = led + 0.01; + * wait(0.2); + * if(led == 1.0) { + * led = 0; + * } + * } + * } + * @endcode + * + * @note + * On the LPC1768 and LPC2368, the PWMs all share the same + * period - if you change the period for one, you change it for all. + * Although routines that change the period maintain the duty cycle + * for its PWM, all other PWMs will require their duty cycle to be + * refreshed. + */ +class PwmOut { + +public: + + /** Create a PwmOut connected to the specified pin + * + * @param pin PwmOut pin to connect to + */ + PwmOut(PinName pin) { + pwmout_init(&_pwm, pin); + } + + /** Set the ouput duty-cycle, specified as a percentage (float) + * + * @param value A floating-point value representing the output duty-cycle, + * specified as a percentage. The value should lie between + * 0.0f (representing on 0%) and 1.0f (representing on 100%). + * Values outside this range will be saturated to 0.0f or 1.0f. + */ + void write(float value) { + pwmout_write(&_pwm, value); + } + + /** Return the current output duty-cycle setting, measured as a percentage (float) + * + * @returns + * A floating-point value representing the current duty-cycle being output on the pin, + * measured as a percentage. The returned value will lie between + * 0.0f (representing on 0%) and 1.0f (representing on 100%). + * + * @note + * This value may not match exactly the value set by a previous <write>. + */ + float read() { + return pwmout_read(&_pwm); + } + + /** Set the PWM period, specified in seconds (float), keeping the duty cycle the same. + * + * @note + * The resolution is currently in microseconds; periods smaller than this + * will be set to zero. + */ + void period(float seconds) { + pwmout_period(&_pwm, seconds); + } + + /** Set the PWM period, specified in milli-seconds (int), keeping the duty cycle the same. + */ + void period_ms(int ms) { + pwmout_period_ms(&_pwm, ms); + } + + /** Set the PWM period, specified in micro-seconds (int), keeping the duty cycle the same. + */ + void period_us(int us) { + pwmout_period_us(&_pwm, us); + } + + /** Set the PWM pulsewidth, specified in seconds (float), keeping the period the same. + */ + void pulsewidth(float seconds) { + pwmout_pulsewidth(&_pwm, seconds); + } + + /** Set the PWM pulsewidth, specified in milli-seconds (int), keeping the period the same. + */ + void pulsewidth_ms(int ms) { + pwmout_pulsewidth_ms(&_pwm, ms); + } + + /** Set the PWM pulsewidth, specified in micro-seconds (int), keeping the period the same. + */ + void pulsewidth_us(int us) { + pwmout_pulsewidth_us(&_pwm, us); + } + +#ifdef MBED_OPERATORS + /** A operator shorthand for write() + */ + PwmOut& operator= (float value) { + write(value); + return *this; + } + + PwmOut& operator= (PwmOut& rhs) { + write(rhs.read()); + return *this; + } + + /** An operator shorthand for read() + */ + operator float() { + return read(); + } +#endif + +protected: + pwmout_t _pwm; +}; + +} // namespace mbed + +#endif + +#endif