mbed library sources. Supersedes mbed-src.
Dependents: Nucleo_Hello_Encoder BLE_iBeaconScan AM1805_DEMO DISCO-F429ZI_ExportTemplate1 ... more
PwmOut.h
00001 /* mbed Microcontroller Library 00002 * Copyright (c) 2006-2013 ARM Limited 00003 * SPDX-License-Identifier: Apache-2.0 00004 * 00005 * Licensed under the Apache License, Version 2.0 (the "License"); 00006 * you may not use this file except in compliance with the License. 00007 * You may obtain a copy of the License at 00008 * 00009 * http://www.apache.org/licenses/LICENSE-2.0 00010 * 00011 * Unless required by applicable law or agreed to in writing, software 00012 * distributed under the License is distributed on an "AS IS" BASIS, 00013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 00014 * See the License for the specific language governing permissions and 00015 * limitations under the License. 00016 */ 00017 #ifndef MBED_PWMOUT_H 00018 #define MBED_PWMOUT_H 00019 00020 #include "platform/platform.h" 00021 00022 #if DEVICE_PWMOUT || defined(DOXYGEN_ONLY) 00023 #include "hal/pwmout_api.h" 00024 #include "platform/mbed_critical.h" 00025 #include "platform/mbed_power_mgmt.h" 00026 00027 namespace mbed { 00028 /** \addtogroup drivers */ 00029 00030 /** A pulse-width modulation digital output 00031 * 00032 * @note Synchronization level: Interrupt safe 00033 * 00034 * Example 00035 * @code 00036 * // Gradually change the intensity of the LED. 00037 * #include "mbed.h" 00038 * 00039 * PwmOut led(LED1); 00040 * 00041 * int main() { 00042 * while(1) { 00043 * led = led + 0.01; 00044 * wait(0.2); 00045 * if(led == 1.0) { 00046 * led = 0; 00047 * } 00048 * } 00049 * } 00050 * @endcode 00051 * @ingroup drivers 00052 */ 00053 class PwmOut { 00054 00055 public: 00056 00057 /** Create a PwmOut connected to the specified pin 00058 * 00059 * @param pin PwmOut pin to connect to 00060 */ 00061 PwmOut(PinName pin) : _deep_sleep_locked(false) 00062 { 00063 core_util_critical_section_enter(); 00064 pwmout_init(&_pwm, pin); 00065 core_util_critical_section_exit(); 00066 } 00067 00068 ~PwmOut() 00069 { 00070 core_util_critical_section_enter(); 00071 unlock_deep_sleep(); 00072 core_util_critical_section_exit(); 00073 } 00074 00075 /** Set the output duty-cycle, specified as a percentage (float) 00076 * 00077 * @param value A floating-point value representing the output duty-cycle, 00078 * specified as a percentage. The value should lie between 00079 * 0.0f (representing on 0%) and 1.0f (representing on 100%). 00080 * Values outside this range will be saturated to 0.0f or 1.0f. 00081 */ 00082 void write(float value) 00083 { 00084 core_util_critical_section_enter(); 00085 lock_deep_sleep(); 00086 pwmout_write(&_pwm, value); 00087 core_util_critical_section_exit(); 00088 } 00089 00090 /** Return the current output duty-cycle setting, measured as a percentage (float) 00091 * 00092 * @returns 00093 * A floating-point value representing the current duty-cycle being output on the pin, 00094 * measured as a percentage. The returned value will lie between 00095 * 0.0f (representing on 0%) and 1.0f (representing on 100%). 00096 * 00097 * @note 00098 * This value may not match exactly the value set by a previous write(). 00099 */ 00100 float read() 00101 { 00102 core_util_critical_section_enter(); 00103 float val = pwmout_read(&_pwm); 00104 core_util_critical_section_exit(); 00105 return val; 00106 } 00107 00108 /** Set the PWM period, specified in seconds (float), keeping the duty cycle the same. 00109 * 00110 * @param seconds Change the period of a PWM signal in seconds (float) without modifying the duty cycle 00111 * @note 00112 * The resolution is currently in microseconds; periods smaller than this 00113 * will be set to zero. 00114 */ 00115 void period(float seconds) 00116 { 00117 core_util_critical_section_enter(); 00118 pwmout_period(&_pwm, seconds); 00119 core_util_critical_section_exit(); 00120 } 00121 00122 /** Set the PWM period, specified in milliseconds (int), keeping the duty cycle the same. 00123 * @param ms Change the period of a PWM signal in milliseconds without modifying the duty cycle 00124 */ 00125 void period_ms(int ms) 00126 { 00127 core_util_critical_section_enter(); 00128 pwmout_period_ms(&_pwm, ms); 00129 core_util_critical_section_exit(); 00130 } 00131 00132 /** Set the PWM period, specified in microseconds (int), keeping the duty cycle the same. 00133 * @param us Change the period of a PWM signal in microseconds without modifying the duty cycle 00134 */ 00135 void period_us(int us) 00136 { 00137 core_util_critical_section_enter(); 00138 pwmout_period_us(&_pwm, us); 00139 core_util_critical_section_exit(); 00140 } 00141 00142 /** Set the PWM pulsewidth, specified in seconds (float), keeping the period the same. 00143 * @param seconds Change the pulse width of a PWM signal specified in seconds (float) 00144 */ 00145 void pulsewidth(float seconds) 00146 { 00147 core_util_critical_section_enter(); 00148 pwmout_pulsewidth(&_pwm, seconds); 00149 core_util_critical_section_exit(); 00150 } 00151 00152 /** Set the PWM pulsewidth, specified in milliseconds (int), keeping the period the same. 00153 * @param ms Change the pulse width of a PWM signal specified in milliseconds 00154 */ 00155 void pulsewidth_ms(int ms) 00156 { 00157 core_util_critical_section_enter(); 00158 pwmout_pulsewidth_ms(&_pwm, ms); 00159 core_util_critical_section_exit(); 00160 } 00161 00162 /** Set the PWM pulsewidth, specified in microseconds (int), keeping the period the same. 00163 * @param us Change the pulse width of a PWM signal specified in microseconds 00164 */ 00165 void pulsewidth_us(int us) 00166 { 00167 core_util_critical_section_enter(); 00168 pwmout_pulsewidth_us(&_pwm, us); 00169 core_util_critical_section_exit(); 00170 } 00171 00172 /** A operator shorthand for write() 00173 * \sa PwmOut::write() 00174 */ 00175 PwmOut &operator= (float value) 00176 { 00177 // Underlying call is thread safe 00178 write(value); 00179 return *this; 00180 } 00181 00182 /** A operator shorthand for write() 00183 * \sa PwmOut::write() 00184 */ 00185 PwmOut &operator= (PwmOut &rhs) 00186 { 00187 // Underlying call is thread safe 00188 write(rhs.read()); 00189 return *this; 00190 } 00191 00192 /** An operator shorthand for read() 00193 * \sa PwmOut::read() 00194 */ 00195 operator float() 00196 { 00197 // Underlying call is thread safe 00198 return read(); 00199 } 00200 00201 #if !(DOXYGEN_ONLY) 00202 protected: 00203 /** Lock deep sleep only if it is not yet locked */ 00204 void lock_deep_sleep() 00205 { 00206 if (_deep_sleep_locked == false) { 00207 sleep_manager_lock_deep_sleep(); 00208 _deep_sleep_locked = true; 00209 } 00210 } 00211 00212 /** Unlock deep sleep in case it is locked */ 00213 void unlock_deep_sleep() 00214 { 00215 if (_deep_sleep_locked == true) { 00216 sleep_manager_unlock_deep_sleep(); 00217 _deep_sleep_locked = false; 00218 } 00219 } 00220 00221 pwmout_t _pwm; 00222 bool _deep_sleep_locked; 00223 #endif 00224 }; 00225 00226 } // namespace mbed 00227 00228 #endif 00229 00230 #endif
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