mbed library sources. Supersedes mbed-src.
Dependents: Hobbyking_Cheetah_Compact Hobbyking_Cheetah_Compact_DRV8323_14bit Hobbyking_Cheetah_Compact_DRV8323_V51_201907 HKC_MiniCheetah ... more
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drivers/PwmOut.h
- Committer:
- benkatz
- Date:
- 2018-07-30
- Revision:
- 181:36facd806e4a
- Parent:
- 175:af195413fb11
File content as of revision 181:36facd806e4a:
/* 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_PWMOUT_H #define MBED_PWMOUT_H #include "platform/platform.h" #if defined (DEVICE_PWMOUT) || defined(DOXYGEN_ONLY) #include "hal/pwmout_api.h" #include "platform/mbed_critical.h" #include "platform/mbed_sleep.h" namespace mbed { /** \addtogroup drivers */ /** A pulse-width modulation digital output * * @note Synchronization level: Interrupt safe * * 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 * @ingroup drivers */ class PwmOut { public: /** Create a PwmOut connected to the specified pin * * @param pin PwmOut pin to connect to */ PwmOut(PinName pin) : _deep_sleep_locked(false) { core_util_critical_section_enter(); pwmout_init(&_pwm, pin); core_util_critical_section_exit(); } ~PwmOut() { core_util_critical_section_enter(); unlock_deep_sleep(); core_util_critical_section_exit(); } /** 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) { core_util_critical_section_enter(); lock_deep_sleep(); pwmout_write(&_pwm, value); core_util_critical_section_exit(); } /** 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() { core_util_critical_section_enter(); float val = pwmout_read(&_pwm); core_util_critical_section_exit(); return val; } /** Set the PWM period, specified in seconds (float), keeping the duty cycle the same. * * @param seconds Change the period of a PWM signal in seconds (float) without modifying the duty cycle * @note * The resolution is currently in microseconds; periods smaller than this * will be set to zero. */ void period(float seconds) { core_util_critical_section_enter(); pwmout_period(&_pwm, seconds); core_util_critical_section_exit(); } /** Set the PWM period, specified in milli-seconds (int), keeping the duty cycle the same. * @param ms Change the period of a PWM signal in milli-seconds without modifying the duty cycle */ void period_ms(int ms) { core_util_critical_section_enter(); pwmout_period_ms(&_pwm, ms); core_util_critical_section_exit(); } /** Set the PWM period, specified in micro-seconds (int), keeping the duty cycle the same. * @param us Change the period of a PWM signal in micro-seconds without modifying the duty cycle */ void period_us(int us) { core_util_critical_section_enter(); pwmout_period_us(&_pwm, us); core_util_critical_section_exit(); } /** Set the PWM pulsewidth, specified in seconds (float), keeping the period the same. * @param seconds Change the pulse width of a PWM signal specified in seconds (float) */ void pulsewidth(float seconds) { core_util_critical_section_enter(); pwmout_pulsewidth(&_pwm, seconds); core_util_critical_section_exit(); } /** Set the PWM pulsewidth, specified in milli-seconds (int), keeping the period the same. * @param ms Change the pulse width of a PWM signal specified in milli-seconds */ void pulsewidth_ms(int ms) { core_util_critical_section_enter(); pwmout_pulsewidth_ms(&_pwm, ms); core_util_critical_section_exit(); } /** Set the PWM pulsewidth, specified in micro-seconds (int), keeping the period the same. * @param us Change the pulse width of a PWM signal specified in micro-seconds */ void pulsewidth_us(int us) { core_util_critical_section_enter(); pwmout_pulsewidth_us(&_pwm, us); core_util_critical_section_exit(); } /** A operator shorthand for write() * \sa PwmOut::write() */ PwmOut& operator= (float value) { // Underlying call is thread safe write(value); return *this; } /** A operator shorthand for write() * \sa PwmOut::write() */ PwmOut& operator= (PwmOut& rhs) { // Underlying call is thread safe write(rhs.read()); return *this; } /** An operator shorthand for read() * \sa PwmOut::read() */ operator float() { // Underlying call is thread safe return read(); } protected: /** Lock deep sleep only if it is not yet locked */ void lock_deep_sleep() { if (_deep_sleep_locked == false) { sleep_manager_lock_deep_sleep(); _deep_sleep_locked = true; } } /** Unlock deep sleep in case it is locked */ void unlock_deep_sleep() { if (_deep_sleep_locked == true) { sleep_manager_unlock_deep_sleep(); _deep_sleep_locked = false; } } pwmout_t _pwm; bool _deep_sleep_locked; }; } // namespace mbed #endif #endif