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The official Mbed 2 C/C++ SDK provides the software platform and libraries to build your applications.

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mbed 2

This is the mbed 2 library. If you'd like to learn about Mbed OS please see the mbed-os docs.

drivers/PwmOut.h@172:65be27845400, 2019-02-20 (annotated)

Committer:
AnnaBridge
Date:
Wed Feb 20 20:53:29 2019 +0000
Revision:
172:65be27845400
Parent:
171:3a7713b1edbc 
mbed library release version 165

Who changed what in which revision?

UserRevisionLine numberNew contents of line
AnnaBridge 156:ff21514d8981 1 /* mbed Microcontroller Library
AnnaBridge 156:ff21514d8981 2 * Copyright (c) 2006-2013 ARM Limited
AnnaBridge 172:65be27845400 3 * SPDX-License-Identifier: Apache-2.0
AnnaBridge 156:ff21514d8981 4 *
AnnaBridge 156:ff21514d8981 5 * Licensed under the Apache License, Version 2.0 (the "License");
AnnaBridge 156:ff21514d8981 6 * you may not use this file except in compliance with the License.
AnnaBridge 156:ff21514d8981 7 * You may obtain a copy of the License at
AnnaBridge 156:ff21514d8981 8 *
AnnaBridge 156:ff21514d8981 9 * http://www.apache.org/licenses/LICENSE-2.0
AnnaBridge 156:ff21514d8981 10 *
AnnaBridge 156:ff21514d8981 11 * Unless required by applicable law or agreed to in writing, software
AnnaBridge 156:ff21514d8981 12 * distributed under the License is distributed on an "AS IS" BASIS,
AnnaBridge 156:ff21514d8981 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
AnnaBridge 156:ff21514d8981 14 * See the License for the specific language governing permissions and
AnnaBridge 156:ff21514d8981 15 * limitations under the License.
AnnaBridge 156:ff21514d8981 16 */
AnnaBridge 156:ff21514d8981 17 #ifndef MBED_PWMOUT_H
AnnaBridge 156:ff21514d8981 18 #define MBED_PWMOUT_H
AnnaBridge 156:ff21514d8981 19
AnnaBridge 156:ff21514d8981 20 #include "platform/platform.h"
AnnaBridge 156:ff21514d8981 21
AnnaBridge 172:65be27845400 22 #if DEVICE_PWMOUT || defined(DOXYGEN_ONLY)
AnnaBridge 156:ff21514d8981 23 #include "hal/pwmout_api.h"
AnnaBridge 156:ff21514d8981 24 #include "platform/mbed_critical.h"
AnnaBridge 165:d1b4690b3f8b 25 #include "platform/mbed_power_mgmt.h"
AnnaBridge 156:ff21514d8981 26
AnnaBridge 156:ff21514d8981 27 namespace mbed {
AnnaBridge 156:ff21514d8981 28 /** \addtogroup drivers */
AnnaBridge 156:ff21514d8981 29
AnnaBridge 156:ff21514d8981 30 /** A pulse-width modulation digital output
AnnaBridge 156:ff21514d8981 31 *
AnnaBridge 156:ff21514d8981 32 * @note Synchronization level: Interrupt safe
AnnaBridge 156:ff21514d8981 33 *
AnnaBridge 156:ff21514d8981 34 * Example
AnnaBridge 156:ff21514d8981 35 * @code
AnnaBridge 171:3a7713b1edbc 36 * // Gradually change the intensity of the LED.
AnnaBridge 156:ff21514d8981 37 * #include "mbed.h"
AnnaBridge 156:ff21514d8981 38 *
AnnaBridge 156:ff21514d8981 39 * PwmOut led(LED1);
AnnaBridge 156:ff21514d8981 40 *
AnnaBridge 156:ff21514d8981 41 * int main() {
AnnaBridge 156:ff21514d8981 42 * while(1) {
AnnaBridge 156:ff21514d8981 43 * led = led + 0.01;
AnnaBridge 156:ff21514d8981 44 * wait(0.2);
AnnaBridge 156:ff21514d8981 45 * if(led == 1.0) {
AnnaBridge 156:ff21514d8981 46 * led = 0;
AnnaBridge 156:ff21514d8981 47 * }
AnnaBridge 156:ff21514d8981 48 * }
AnnaBridge 156:ff21514d8981 49 * }
AnnaBridge 156:ff21514d8981 50 * @endcode
AnnaBridge 156:ff21514d8981 51 * @ingroup drivers
AnnaBridge 156:ff21514d8981 52 */
AnnaBridge 156:ff21514d8981 53 class PwmOut {
AnnaBridge 156:ff21514d8981 54
AnnaBridge 156:ff21514d8981 55 public:
AnnaBridge 156:ff21514d8981 56
AnnaBridge 156:ff21514d8981 57 /** Create a PwmOut connected to the specified pin
AnnaBridge 156:ff21514d8981 58 *
AnnaBridge 156:ff21514d8981 59 * @param pin PwmOut pin to connect to
AnnaBridge 156:ff21514d8981 60 */
AnnaBridge 170:e95d10626187 61 PwmOut(PinName pin) : _deep_sleep_locked(false)
AnnaBridge 170:e95d10626187 62 {
AnnaBridge 156:ff21514d8981 63 core_util_critical_section_enter();
AnnaBridge 156:ff21514d8981 64 pwmout_init(&_pwm, pin);
AnnaBridge 156:ff21514d8981 65 core_util_critical_section_exit();
AnnaBridge 156:ff21514d8981 66 }
AnnaBridge 156:ff21514d8981 67
AnnaBridge 170:e95d10626187 68 ~PwmOut()
AnnaBridge 170:e95d10626187 69 {
AnnaBridge 156:ff21514d8981 70 core_util_critical_section_enter();
AnnaBridge 156:ff21514d8981 71 unlock_deep_sleep();
AnnaBridge 156:ff21514d8981 72 core_util_critical_section_exit();
AnnaBridge 156:ff21514d8981 73 }
AnnaBridge 156:ff21514d8981 74
AnnaBridge 171:3a7713b1edbc 75 /** Set the output duty-cycle, specified as a percentage (float)
AnnaBridge 156:ff21514d8981 76 *
AnnaBridge 156:ff21514d8981 77 * @param value A floating-point value representing the output duty-cycle,
AnnaBridge 156:ff21514d8981 78 * specified as a percentage. The value should lie between
AnnaBridge 156:ff21514d8981 79 * 0.0f (representing on 0%) and 1.0f (representing on 100%).
AnnaBridge 156:ff21514d8981 80 * Values outside this range will be saturated to 0.0f or 1.0f.
AnnaBridge 156:ff21514d8981 81 */
AnnaBridge 170:e95d10626187 82 void write(float value)
AnnaBridge 170:e95d10626187 83 {
AnnaBridge 156:ff21514d8981 84 core_util_critical_section_enter();
AnnaBridge 156:ff21514d8981 85 lock_deep_sleep();
AnnaBridge 156:ff21514d8981 86 pwmout_write(&_pwm, value);
AnnaBridge 156:ff21514d8981 87 core_util_critical_section_exit();
AnnaBridge 156:ff21514d8981 88 }
AnnaBridge 156:ff21514d8981 89
AnnaBridge 156:ff21514d8981 90 /** Return the current output duty-cycle setting, measured as a percentage (float)
AnnaBridge 156:ff21514d8981 91 *
AnnaBridge 156:ff21514d8981 92 * @returns
AnnaBridge 156:ff21514d8981 93 * A floating-point value representing the current duty-cycle being output on the pin,
AnnaBridge 156:ff21514d8981 94 * measured as a percentage. The returned value will lie between
AnnaBridge 156:ff21514d8981 95 * 0.0f (representing on 0%) and 1.0f (representing on 100%).
AnnaBridge 156:ff21514d8981 96 *
AnnaBridge 156:ff21514d8981 97 * @note
AnnaBridge 156:ff21514d8981 98 * This value may not match exactly the value set by a previous write().
AnnaBridge 156:ff21514d8981 99 */
AnnaBridge 170:e95d10626187 100 float read()
AnnaBridge 170:e95d10626187 101 {
AnnaBridge 156:ff21514d8981 102 core_util_critical_section_enter();
AnnaBridge 156:ff21514d8981 103 float val = pwmout_read(&_pwm);
AnnaBridge 156:ff21514d8981 104 core_util_critical_section_exit();
AnnaBridge 156:ff21514d8981 105 return val;
AnnaBridge 156:ff21514d8981 106 }
AnnaBridge 156:ff21514d8981 107
AnnaBridge 156:ff21514d8981 108 /** Set the PWM period, specified in seconds (float), keeping the duty cycle the same.
AnnaBridge 156:ff21514d8981 109 *
AnnaBridge 156:ff21514d8981 110 * @param seconds Change the period of a PWM signal in seconds (float) without modifying the duty cycle
AnnaBridge 156:ff21514d8981 111 * @note
AnnaBridge 156:ff21514d8981 112 * The resolution is currently in microseconds; periods smaller than this
AnnaBridge 156:ff21514d8981 113 * will be set to zero.
AnnaBridge 156:ff21514d8981 114 */
AnnaBridge 170:e95d10626187 115 void period(float seconds)
AnnaBridge 170:e95d10626187 116 {
AnnaBridge 156:ff21514d8981 117 core_util_critical_section_enter();
AnnaBridge 156:ff21514d8981 118 pwmout_period(&_pwm, seconds);
AnnaBridge 156:ff21514d8981 119 core_util_critical_section_exit();
AnnaBridge 156:ff21514d8981 120 }
AnnaBridge 156:ff21514d8981 121
AnnaBridge 171:3a7713b1edbc 122 /** Set the PWM period, specified in milliseconds (int), keeping the duty cycle the same.
AnnaBridge 171:3a7713b1edbc 123 * @param ms Change the period of a PWM signal in milliseconds without modifying the duty cycle
AnnaBridge 156:ff21514d8981 124 */
AnnaBridge 170:e95d10626187 125 void period_ms(int ms)
AnnaBridge 170:e95d10626187 126 {
AnnaBridge 156:ff21514d8981 127 core_util_critical_section_enter();
AnnaBridge 156:ff21514d8981 128 pwmout_period_ms(&_pwm, ms);
AnnaBridge 156:ff21514d8981 129 core_util_critical_section_exit();
AnnaBridge 156:ff21514d8981 130 }
AnnaBridge 156:ff21514d8981 131
AnnaBridge 171:3a7713b1edbc 132 /** Set the PWM period, specified in microseconds (int), keeping the duty cycle the same.
AnnaBridge 171:3a7713b1edbc 133 * @param us Change the period of a PWM signal in microseconds without modifying the duty cycle
AnnaBridge 156:ff21514d8981 134 */
AnnaBridge 170:e95d10626187 135 void period_us(int us)
AnnaBridge 170:e95d10626187 136 {
AnnaBridge 156:ff21514d8981 137 core_util_critical_section_enter();
AnnaBridge 156:ff21514d8981 138 pwmout_period_us(&_pwm, us);
AnnaBridge 156:ff21514d8981 139 core_util_critical_section_exit();
AnnaBridge 156:ff21514d8981 140 }
AnnaBridge 156:ff21514d8981 141
AnnaBridge 156:ff21514d8981 142 /** Set the PWM pulsewidth, specified in seconds (float), keeping the period the same.
AnnaBridge 156:ff21514d8981 143 * @param seconds Change the pulse width of a PWM signal specified in seconds (float)
AnnaBridge 156:ff21514d8981 144 */
AnnaBridge 170:e95d10626187 145 void pulsewidth(float seconds)
AnnaBridge 170:e95d10626187 146 {
AnnaBridge 156:ff21514d8981 147 core_util_critical_section_enter();
AnnaBridge 156:ff21514d8981 148 pwmout_pulsewidth(&_pwm, seconds);
AnnaBridge 156:ff21514d8981 149 core_util_critical_section_exit();
AnnaBridge 156:ff21514d8981 150 }
AnnaBridge 156:ff21514d8981 151
AnnaBridge 171:3a7713b1edbc 152 /** Set the PWM pulsewidth, specified in milliseconds (int), keeping the period the same.
AnnaBridge 171:3a7713b1edbc 153 * @param ms Change the pulse width of a PWM signal specified in milliseconds
AnnaBridge 156:ff21514d8981 154 */
AnnaBridge 170:e95d10626187 155 void pulsewidth_ms(int ms)
AnnaBridge 170:e95d10626187 156 {
AnnaBridge 156:ff21514d8981 157 core_util_critical_section_enter();
AnnaBridge 156:ff21514d8981 158 pwmout_pulsewidth_ms(&_pwm, ms);
AnnaBridge 156:ff21514d8981 159 core_util_critical_section_exit();
AnnaBridge 156:ff21514d8981 160 }
AnnaBridge 156:ff21514d8981 161
AnnaBridge 171:3a7713b1edbc 162 /** Set the PWM pulsewidth, specified in microseconds (int), keeping the period the same.
AnnaBridge 171:3a7713b1edbc 163 * @param us Change the pulse width of a PWM signal specified in microseconds
AnnaBridge 156:ff21514d8981 164 */
AnnaBridge 170:e95d10626187 165 void pulsewidth_us(int us)
AnnaBridge 170:e95d10626187 166 {
AnnaBridge 156:ff21514d8981 167 core_util_critical_section_enter();
AnnaBridge 156:ff21514d8981 168 pwmout_pulsewidth_us(&_pwm, us);
AnnaBridge 156:ff21514d8981 169 core_util_critical_section_exit();
AnnaBridge 156:ff21514d8981 170 }
AnnaBridge 156:ff21514d8981 171
AnnaBridge 156:ff21514d8981 172 /** A operator shorthand for write()
AnnaBridge 156:ff21514d8981 173 * \sa PwmOut::write()
AnnaBridge 156:ff21514d8981 174 */
AnnaBridge 170:e95d10626187 175 PwmOut &operator= (float value)
AnnaBridge 170:e95d10626187 176 {
AnnaBridge 156:ff21514d8981 177 // Underlying call is thread safe
AnnaBridge 156:ff21514d8981 178 write(value);
AnnaBridge 156:ff21514d8981 179 return *this;
AnnaBridge 156:ff21514d8981 180 }
AnnaBridge 156:ff21514d8981 181
AnnaBridge 156:ff21514d8981 182 /** A operator shorthand for write()
AnnaBridge 156:ff21514d8981 183 * \sa PwmOut::write()
AnnaBridge 170:e95d10626187 184 */
AnnaBridge 170:e95d10626187 185 PwmOut &operator= (PwmOut &rhs)
AnnaBridge 170:e95d10626187 186 {
AnnaBridge 156:ff21514d8981 187 // Underlying call is thread safe
AnnaBridge 156:ff21514d8981 188 write(rhs.read());
AnnaBridge 156:ff21514d8981 189 return *this;
AnnaBridge 156:ff21514d8981 190 }
AnnaBridge 156:ff21514d8981 191
AnnaBridge 156:ff21514d8981 192 /** An operator shorthand for read()
AnnaBridge 156:ff21514d8981 193 * \sa PwmOut::read()
AnnaBridge 156:ff21514d8981 194 */
AnnaBridge 170:e95d10626187 195 operator float()
AnnaBridge 170:e95d10626187 196 {
AnnaBridge 156:ff21514d8981 197 // Underlying call is thread safe
AnnaBridge 156:ff21514d8981 198 return read();
AnnaBridge 156:ff21514d8981 199 }
AnnaBridge 156:ff21514d8981 200
AnnaBridge 171:3a7713b1edbc 201 #if !(DOXYGEN_ONLY)
AnnaBridge 156:ff21514d8981 202 protected:
AnnaBridge 156:ff21514d8981 203 /** Lock deep sleep only if it is not yet locked */
AnnaBridge 170:e95d10626187 204 void lock_deep_sleep()
AnnaBridge 170:e95d10626187 205 {
AnnaBridge 156:ff21514d8981 206 if (_deep_sleep_locked == false) {
AnnaBridge 156:ff21514d8981 207 sleep_manager_lock_deep_sleep();
AnnaBridge 156:ff21514d8981 208 _deep_sleep_locked = true;
AnnaBridge 156:ff21514d8981 209 }
AnnaBridge 156:ff21514d8981 210 }
AnnaBridge 156:ff21514d8981 211
AnnaBridge 156:ff21514d8981 212 /** Unlock deep sleep in case it is locked */
AnnaBridge 170:e95d10626187 213 void unlock_deep_sleep()
AnnaBridge 170:e95d10626187 214 {
AnnaBridge 156:ff21514d8981 215 if (_deep_sleep_locked == true) {
AnnaBridge 156:ff21514d8981 216 sleep_manager_unlock_deep_sleep();
AnnaBridge 156:ff21514d8981 217 _deep_sleep_locked = false;
AnnaBridge 156:ff21514d8981 218 }
AnnaBridge 156:ff21514d8981 219 }
AnnaBridge 156:ff21514d8981 220
AnnaBridge 156:ff21514d8981 221 pwmout_t _pwm;
AnnaBridge 156:ff21514d8981 222 bool _deep_sleep_locked;
AnnaBridge 171:3a7713b1edbc 223 #endif
AnnaBridge 156:ff21514d8981 224 };
AnnaBridge 156:ff21514d8981 225
AnnaBridge 156:ff21514d8981 226 } // namespace mbed
AnnaBridge 156:ff21514d8981 227
AnnaBridge 156:ff21514d8981 228 #endif
AnnaBridge 156:ff21514d8981 229
AnnaBridge 156:ff21514d8981 230 #endif