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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@160:5571c4ff569f, 2018-01-17 (annotated)

Committer:
Anna Bridge
Date:
Wed Jan 17 16:13:02 2018 +0000
Revision:
160:5571c4ff569f
Parent:
156:ff21514d8981
Child:
165:d1b4690b3f8b
mbed library. Release version 158

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