mbed official / mbed-dev

mbed library sources. Supersedes mbed-src.

Dependents:   Nucleo_Hello_Encoder BLE_iBeaconScan AM1805_DEMO DISCO-F429ZI_ExportTemplate1 ... more

drivers/PwmOut.h@181:57724642e740, 2018-02-16 (annotated)

Committer:
AnnaBridge
Date:
Fri Feb 16 16:09:33 2018 +0000
Revision:
181:57724642e740
Parent:
175:af195413fb11
Child:
184:08ed48f1de7f
mbed-dev library. Release version 159.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
<> 149:156823d33999 1 /* mbed Microcontroller Library
<> 149:156823d33999 2 * Copyright (c) 2006-2013 ARM Limited
<> 149:156823d33999 3 *
<> 149:156823d33999 4 * Licensed under the Apache License, Version 2.0 (the "License");
<> 149:156823d33999 5 * you may not use this file except in compliance with the License.
<> 149:156823d33999 6 * You may obtain a copy of the License at
<> 149:156823d33999 7 *
<> 149:156823d33999 8 * http://www.apache.org/licenses/LICENSE-2.0
<> 149:156823d33999 9 *
<> 149:156823d33999 10 * Unless required by applicable law or agreed to in writing, software
<> 149:156823d33999 11 * distributed under the License is distributed on an "AS IS" BASIS,
<> 149:156823d33999 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
<> 149:156823d33999 13 * See the License for the specific language governing permissions and
<> 149:156823d33999 14 * limitations under the License.
<> 149:156823d33999 15 */
<> 149:156823d33999 16 #ifndef MBED_PWMOUT_H
<> 149:156823d33999 17 #define MBED_PWMOUT_H
<> 149:156823d33999 18
<> 149:156823d33999 19 #include "platform/platform.h"
<> 149:156823d33999 20
AnnaBridge 167:e84263d55307 21 #if defined (DEVICE_PWMOUT) || defined(DOXYGEN_ONLY)
<> 149:156823d33999 22 #include "hal/pwmout_api.h"
<> 160:d5399cc887bb 23 #include "platform/mbed_critical.h"
AnnaBridge 175:af195413fb11 24 #include "platform/mbed_sleep.h"
<> 149:156823d33999 25
<> 149:156823d33999 26 namespace mbed {
<> 149:156823d33999 27 /** \addtogroup drivers */
<> 149:156823d33999 28
<> 149:156823d33999 29 /** A pulse-width modulation digital output
<> 149:156823d33999 30 *
AnnaBridge 167:e84263d55307 31 * @note Synchronization level: Interrupt safe
<> 149:156823d33999 32 *
<> 149:156823d33999 33 * Example
<> 149:156823d33999 34 * @code
<> 149:156823d33999 35 * // Fade a led on.
<> 149:156823d33999 36 * #include "mbed.h"
<> 149:156823d33999 37 *
<> 149:156823d33999 38 * PwmOut led(LED1);
<> 149:156823d33999 39 *
<> 149:156823d33999 40 * int main() {
<> 149:156823d33999 41 * while(1) {
<> 149:156823d33999 42 * led = led + 0.01;
<> 149:156823d33999 43 * wait(0.2);
<> 149:156823d33999 44 * if(led == 1.0) {
<> 149:156823d33999 45 * led = 0;
<> 149:156823d33999 46 * }
<> 149:156823d33999 47 * }
<> 149:156823d33999 48 * }
<> 149:156823d33999 49 * @endcode
AnnaBridge 167:e84263d55307 50 * @ingroup drivers
<> 149:156823d33999 51 */
<> 149:156823d33999 52 class PwmOut {
<> 149:156823d33999 53
<> 149:156823d33999 54 public:
<> 149:156823d33999 55
<> 149:156823d33999 56 /** Create a PwmOut connected to the specified pin
<> 149:156823d33999 57 *
<> 149:156823d33999 58 * @param pin PwmOut pin to connect to
<> 149:156823d33999 59 */
AnnaBridge 175:af195413fb11 60 PwmOut(PinName pin) : _deep_sleep_locked(false) {
<> 149:156823d33999 61 core_util_critical_section_enter();
<> 149:156823d33999 62 pwmout_init(&_pwm, pin);
<> 149:156823d33999 63 core_util_critical_section_exit();
<> 149:156823d33999 64 }
<> 149:156823d33999 65
AnnaBridge 175:af195413fb11 66 ~PwmOut() {
AnnaBridge 175:af195413fb11 67 core_util_critical_section_enter();
AnnaBridge 175:af195413fb11 68 unlock_deep_sleep();
AnnaBridge 175:af195413fb11 69 core_util_critical_section_exit();
AnnaBridge 175:af195413fb11 70 }
AnnaBridge 175:af195413fb11 71
<> 149:156823d33999 72 /** Set the ouput duty-cycle, specified as a percentage (float)
<> 149:156823d33999 73 *
<> 149:156823d33999 74 * @param value A floating-point value representing the output duty-cycle,
<> 149:156823d33999 75 * specified as a percentage. The value should lie between
<> 149:156823d33999 76 * 0.0f (representing on 0%) and 1.0f (representing on 100%).
<> 149:156823d33999 77 * Values outside this range will be saturated to 0.0f or 1.0f.
<> 149:156823d33999 78 */
<> 149:156823d33999 79 void write(float value) {
<> 149:156823d33999 80 core_util_critical_section_enter();
AnnaBridge 175:af195413fb11 81 lock_deep_sleep();
<> 149:156823d33999 82 pwmout_write(&_pwm, value);
<> 149:156823d33999 83 core_util_critical_section_exit();
<> 149:156823d33999 84 }
<> 149:156823d33999 85
<> 149:156823d33999 86 /** Return the current output duty-cycle setting, measured as a percentage (float)
<> 149:156823d33999 87 *
<> 149:156823d33999 88 * @returns
<> 149:156823d33999 89 * A floating-point value representing the current duty-cycle being output on the pin,
<> 149:156823d33999 90 * measured as a percentage. The returned value will lie between
<> 149:156823d33999 91 * 0.0f (representing on 0%) and 1.0f (representing on 100%).
<> 149:156823d33999 92 *
<> 149:156823d33999 93 * @note
AnnaBridge 167:e84263d55307 94 * This value may not match exactly the value set by a previous write().
<> 149:156823d33999 95 */
<> 149:156823d33999 96 float read() {
<> 149:156823d33999 97 core_util_critical_section_enter();
<> 149:156823d33999 98 float val = pwmout_read(&_pwm);
<> 149:156823d33999 99 core_util_critical_section_exit();
<> 149:156823d33999 100 return val;
<> 149:156823d33999 101 }
<> 149:156823d33999 102
<> 149:156823d33999 103 /** Set the PWM period, specified in seconds (float), keeping the duty cycle the same.
<> 149:156823d33999 104 *
AnnaBridge 167:e84263d55307 105 * @param seconds Change the period of a PWM signal in seconds (float) without modifying the duty cycle
<> 149:156823d33999 106 * @note
<> 149:156823d33999 107 * The resolution is currently in microseconds; periods smaller than this
<> 149:156823d33999 108 * will be set to zero.
<> 149:156823d33999 109 */
<> 149:156823d33999 110 void period(float seconds) {
<> 149:156823d33999 111 core_util_critical_section_enter();
<> 149:156823d33999 112 pwmout_period(&_pwm, seconds);
<> 149:156823d33999 113 core_util_critical_section_exit();
<> 149:156823d33999 114 }
<> 149:156823d33999 115
<> 149:156823d33999 116 /** Set the PWM period, specified in milli-seconds (int), keeping the duty cycle the same.
AnnaBridge 167:e84263d55307 117 * @param ms Change the period of a PWM signal in milli-seconds without modifying the duty cycle
<> 149:156823d33999 118 */
<> 149:156823d33999 119 void period_ms(int ms) {
<> 149:156823d33999 120 core_util_critical_section_enter();
<> 149:156823d33999 121 pwmout_period_ms(&_pwm, ms);
<> 149:156823d33999 122 core_util_critical_section_exit();
<> 149:156823d33999 123 }
<> 149:156823d33999 124
<> 149:156823d33999 125 /** Set the PWM period, specified in micro-seconds (int), keeping the duty cycle the same.
AnnaBridge 167:e84263d55307 126 * @param us Change the period of a PWM signal in micro-seconds without modifying the duty cycle
<> 149:156823d33999 127 */
<> 149:156823d33999 128 void period_us(int us) {
<> 149:156823d33999 129 core_util_critical_section_enter();
<> 149:156823d33999 130 pwmout_period_us(&_pwm, us);
<> 149:156823d33999 131 core_util_critical_section_exit();
<> 149:156823d33999 132 }
<> 149:156823d33999 133
<> 149:156823d33999 134 /** Set the PWM pulsewidth, specified in seconds (float), keeping the period the same.
AnnaBridge 167:e84263d55307 135 * @param seconds Change the pulse width of a PWM signal specified in seconds (float)
<> 149:156823d33999 136 */
<> 149:156823d33999 137 void pulsewidth(float seconds) {
<> 149:156823d33999 138 core_util_critical_section_enter();
<> 149:156823d33999 139 pwmout_pulsewidth(&_pwm, seconds);
<> 149:156823d33999 140 core_util_critical_section_exit();
<> 149:156823d33999 141 }
<> 149:156823d33999 142
<> 149:156823d33999 143 /** Set the PWM pulsewidth, specified in milli-seconds (int), keeping the period the same.
AnnaBridge 167:e84263d55307 144 * @param ms Change the pulse width of a PWM signal specified in milli-seconds
<> 149:156823d33999 145 */
<> 149:156823d33999 146 void pulsewidth_ms(int ms) {
<> 149:156823d33999 147 core_util_critical_section_enter();
<> 149:156823d33999 148 pwmout_pulsewidth_ms(&_pwm, ms);
<> 149:156823d33999 149 core_util_critical_section_exit();
<> 149:156823d33999 150 }
<> 149:156823d33999 151
<> 149:156823d33999 152 /** Set the PWM pulsewidth, specified in micro-seconds (int), keeping the period the same.
AnnaBridge 167:e84263d55307 153 * @param us Change the pulse width of a PWM signal specified in micro-seconds
<> 149:156823d33999 154 */
<> 149:156823d33999 155 void pulsewidth_us(int us) {
<> 149:156823d33999 156 core_util_critical_section_enter();
<> 149:156823d33999 157 pwmout_pulsewidth_us(&_pwm, us);
<> 149:156823d33999 158 core_util_critical_section_exit();
<> 149:156823d33999 159 }
<> 149:156823d33999 160
<> 149:156823d33999 161 /** A operator shorthand for write()
AnnaBridge 167:e84263d55307 162 * \sa PwmOut::write()
<> 149:156823d33999 163 */
<> 149:156823d33999 164 PwmOut& operator= (float value) {
<> 149:156823d33999 165 // Underlying call is thread safe
<> 149:156823d33999 166 write(value);
<> 149:156823d33999 167 return *this;
<> 149:156823d33999 168 }
<> 149:156823d33999 169
AnnaBridge 167:e84263d55307 170 /** A operator shorthand for write()
AnnaBridge 167:e84263d55307 171 * \sa PwmOut::write()
AnnaBridge 167:e84263d55307 172 */
<> 149:156823d33999 173 PwmOut& operator= (PwmOut& rhs) {
<> 149:156823d33999 174 // Underlying call is thread safe
<> 149:156823d33999 175 write(rhs.read());
<> 149:156823d33999 176 return *this;
<> 149:156823d33999 177 }
<> 149:156823d33999 178
<> 149:156823d33999 179 /** An operator shorthand for read()
AnnaBridge 167:e84263d55307 180 * \sa PwmOut::read()
<> 149:156823d33999 181 */
<> 149:156823d33999 182 operator float() {
<> 149:156823d33999 183 // Underlying call is thread safe
<> 149:156823d33999 184 return read();
<> 149:156823d33999 185 }
<> 149:156823d33999 186
<> 149:156823d33999 187 protected:
AnnaBridge 175:af195413fb11 188 /** Lock deep sleep only if it is not yet locked */
AnnaBridge 175:af195413fb11 189 void lock_deep_sleep() {
AnnaBridge 175:af195413fb11 190 if (_deep_sleep_locked == false) {
AnnaBridge 175:af195413fb11 191 sleep_manager_lock_deep_sleep();
AnnaBridge 175:af195413fb11 192 _deep_sleep_locked = true;
AnnaBridge 175:af195413fb11 193 }
AnnaBridge 175:af195413fb11 194 }
AnnaBridge 175:af195413fb11 195
AnnaBridge 175:af195413fb11 196 /** Unlock deep sleep in case it is locked */
AnnaBridge 175:af195413fb11 197 void unlock_deep_sleep() {
AnnaBridge 175:af195413fb11 198 if (_deep_sleep_locked == true) {
AnnaBridge 175:af195413fb11 199 sleep_manager_unlock_deep_sleep();
AnnaBridge 175:af195413fb11 200 _deep_sleep_locked = false;
AnnaBridge 175:af195413fb11 201 }
AnnaBridge 175:af195413fb11 202 }
AnnaBridge 175:af195413fb11 203
<> 149:156823d33999 204 pwmout_t _pwm;
AnnaBridge 175:af195413fb11 205 bool _deep_sleep_locked;
<> 149:156823d33999 206 };
<> 149:156823d33999 207
<> 149:156823d33999 208 } // namespace mbed
<> 149:156823d33999 209
<> 149:156823d33999 210 #endif
<> 149:156823d33999 211
<> 149:156823d33999 212 #endif