Martin Woolley / microbit-dal

Solution for Bluetooth SIG hands-on training course

Dependencies:   BLE_API mbed-dev-bin nRF51822-bluetooth-mdw

Dependents:   microbit

Fork of microbit-dal-bluetooth-mdw_starter by Martin Woolley

source/drivers/DynamicPwm.cpp@22:23d7b9a4b082, 2016-07-13 (annotated)

Committer:
LancasterUniversity
Date:
Wed Jul 13 12:17:54 2016 +0100
Revision:
22:23d7b9a4b082
Parent:
3:d86a4ddc1867 
Synchronized with git rev 7cf98c22

Author: James Devine

microbit-dal: patch for fiber_wake_on_event



fiber_wake_on_event used to crash after forking a FOB fiber.



It would attempt to obtain a new fiber context, and would place it on the wait queue.

Then when that fiber was paged in, the context of that fiber would not have been

initialised, as the function presumed schedule would be called immediately after

fiber initialisation.



This patch catches that edge case.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Jonathan Austin 1:8aa5cdb4ab67 1 /*
Jonathan Austin 1:8aa5cdb4ab67 2 The MIT License (MIT)
Jonathan Austin 1:8aa5cdb4ab67 3
Jonathan Austin 1:8aa5cdb4ab67 4 Copyright (c) 2016 British Broadcasting Corporation.
Jonathan Austin 1:8aa5cdb4ab67 5 This software is provided by Lancaster University by arrangement with the BBC.
Jonathan Austin 1:8aa5cdb4ab67 6
Jonathan Austin 1:8aa5cdb4ab67 7 Permission is hereby granted, free of charge, to any person obtaining a
Jonathan Austin 1:8aa5cdb4ab67 8 copy of this software and associated documentation files (the "Software"),
Jonathan Austin 1:8aa5cdb4ab67 9 to deal in the Software without restriction, including without limitation
Jonathan Austin 1:8aa5cdb4ab67 10 the rights to use, copy, modify, merge, publish, distribute, sublicense,
Jonathan Austin 1:8aa5cdb4ab67 11 and/or sell copies of the Software, and to permit persons to whom the
Jonathan Austin 1:8aa5cdb4ab67 12 Software is furnished to do so, subject to the following conditions:
Jonathan Austin 1:8aa5cdb4ab67 13
Jonathan Austin 1:8aa5cdb4ab67 14 The above copyright notice and this permission notice shall be included in
Jonathan Austin 1:8aa5cdb4ab67 15 all copies or substantial portions of the Software.
Jonathan Austin 1:8aa5cdb4ab67 16
Jonathan Austin 1:8aa5cdb4ab67 17 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
Jonathan Austin 1:8aa5cdb4ab67 18 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
Jonathan Austin 1:8aa5cdb4ab67 19 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
Jonathan Austin 1:8aa5cdb4ab67 20 THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
Jonathan Austin 1:8aa5cdb4ab67 21 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
Jonathan Austin 1:8aa5cdb4ab67 22 FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
Jonathan Austin 1:8aa5cdb4ab67 23 DEALINGS IN THE SOFTWARE.
Jonathan Austin 1:8aa5cdb4ab67 24 */
Jonathan Austin 1:8aa5cdb4ab67 25
Jonathan Austin 1:8aa5cdb4ab67 26 /**
Jonathan Austin 1:8aa5cdb4ab67 27 * Class definition for DynamicPwm.
Jonathan Austin 1:8aa5cdb4ab67 28 *
Jonathan Austin 1:8aa5cdb4ab67 29 * This class addresses a few issues found in the underlying libraries.
Jonathan Austin 1:8aa5cdb4ab67 30 * This provides the ability for a neat, clean swap between PWM channels.
Jonathan Austin 1:8aa5cdb4ab67 31 */
Jonathan Austin 1:8aa5cdb4ab67 32
Jonathan Austin 1:8aa5cdb4ab67 33 #include "MicroBitConfig.h"
Jonathan Austin 1:8aa5cdb4ab67 34 #include "DynamicPwm.h"
Jonathan Austin 1:8aa5cdb4ab67 35 #include "MicroBitPin.h"
Jonathan Austin 1:8aa5cdb4ab67 36 #include "ErrorNo.h"
Jonathan Austin 1:8aa5cdb4ab67 37
LancasterUniversity 3:d86a4ddc1867 38 DynamicPwm* DynamicPwm::pwms[NO_PWMS] = { NULL, NULL, NULL };
Jonathan Austin 1:8aa5cdb4ab67 39
Jonathan Austin 1:8aa5cdb4ab67 40 uint8_t DynamicPwm::lastUsed = NO_PWMS+1; //set it to out of range i.e. 4 so we know it hasn't been used yet.
Jonathan Austin 1:8aa5cdb4ab67 41
Jonathan Austin 1:8aa5cdb4ab67 42 uint16_t DynamicPwm::sharedPeriod = 0; //set the shared period to an unknown state
Jonathan Austin 1:8aa5cdb4ab67 43
Jonathan Austin 1:8aa5cdb4ab67 44 /**
Jonathan Austin 1:8aa5cdb4ab67 45 * Reassigns an already operational PWM channel to the given pin.
Jonathan Austin 1:8aa5cdb4ab67 46 *
Jonathan Austin 1:8aa5cdb4ab67 47 * @param pin The desired pin to begin a PWM wave.
Jonathan Austin 1:8aa5cdb4ab67 48 *
Jonathan Austin 1:8aa5cdb4ab67 49 * @param oldPin The pin to stop running a PWM wave.
Jonathan Austin 1:8aa5cdb4ab67 50 *
Jonathan Austin 1:8aa5cdb4ab67 51 * @param channel_number The GPIOTE channel being used to drive this PWM channel
Jonathan Austin 1:8aa5cdb4ab67 52 *
Jonathan Austin 1:8aa5cdb4ab67 53 * TODO: Merge into mbed, at a later date.
Jonathan Austin 1:8aa5cdb4ab67 54 */
Jonathan Austin 1:8aa5cdb4ab67 55 void gpiote_reinit(PinName pin, PinName oldPin, uint8_t channel_number)
Jonathan Austin 1:8aa5cdb4ab67 56 {
Jonathan Austin 1:8aa5cdb4ab67 57 // Connect GPIO input buffers and configure PWM_OUTPUT_PIN_NUMBER as an output.
Jonathan Austin 1:8aa5cdb4ab67 58 NRF_GPIO->PIN_CNF[pin] = (GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos)
Jonathan Austin 1:8aa5cdb4ab67 59 | (GPIO_PIN_CNF_DRIVE_S0S1 << GPIO_PIN_CNF_DRIVE_Pos)
Jonathan Austin 1:8aa5cdb4ab67 60 | (GPIO_PIN_CNF_PULL_Disabled << GPIO_PIN_CNF_PULL_Pos)
Jonathan Austin 1:8aa5cdb4ab67 61 | (GPIO_PIN_CNF_INPUT_Connect << GPIO_PIN_CNF_INPUT_Pos)
Jonathan Austin 1:8aa5cdb4ab67 62 | (GPIO_PIN_CNF_DIR_Output << GPIO_PIN_CNF_DIR_Pos);
Jonathan Austin 1:8aa5cdb4ab67 63
Jonathan Austin 1:8aa5cdb4ab67 64 NRF_GPIO->OUTCLR = (1 << oldPin);
Jonathan Austin 1:8aa5cdb4ab67 65 NRF_GPIO->OUTCLR = (1 << pin);
Jonathan Austin 1:8aa5cdb4ab67 66
Jonathan Austin 1:8aa5cdb4ab67 67 /* Finally configure the channel as the caller expects. If OUTINIT works, the channel is configured properly.
Jonathan Austin 1:8aa5cdb4ab67 68 If it does not, the channel output inheritance sets the proper level. */
Jonathan Austin 1:8aa5cdb4ab67 69
Jonathan Austin 1:8aa5cdb4ab67 70 NRF_GPIOTE->CONFIG[channel_number] = (GPIOTE_CONFIG_MODE_Task << GPIOTE_CONFIG_MODE_Pos) |
Jonathan Austin 1:8aa5cdb4ab67 71 ((uint32_t)pin << GPIOTE_CONFIG_PSEL_Pos) |
Jonathan Austin 1:8aa5cdb4ab67 72 ((uint32_t)GPIOTE_CONFIG_POLARITY_Toggle << GPIOTE_CONFIG_POLARITY_Pos) |
Jonathan Austin 1:8aa5cdb4ab67 73 ((uint32_t)GPIOTE_CONFIG_OUTINIT_Low << GPIOTE_CONFIG_OUTINIT_Pos); // ((uint32_t)GPIOTE_CONFIG_OUTINIT_High <<
Jonathan Austin 1:8aa5cdb4ab67 74 // GPIOTE_CONFIG_OUTINIT_Pos);//
Jonathan Austin 1:8aa5cdb4ab67 75
Jonathan Austin 1:8aa5cdb4ab67 76 /* Three NOPs are required to make sure configuration is written before setting tasks or getting events */
Jonathan Austin 1:8aa5cdb4ab67 77 __NOP();
Jonathan Austin 1:8aa5cdb4ab67 78 __NOP();
Jonathan Austin 1:8aa5cdb4ab67 79 __NOP();
Jonathan Austin 1:8aa5cdb4ab67 80
Jonathan Austin 1:8aa5cdb4ab67 81 NRF_TIMER2->CC[channel_number] = 0;
Jonathan Austin 1:8aa5cdb4ab67 82 }
Jonathan Austin 1:8aa5cdb4ab67 83
Jonathan Austin 1:8aa5cdb4ab67 84 /**
Jonathan Austin 1:8aa5cdb4ab67 85 * An internal constructor used when allocating a new DynamicPwm instance.
Jonathan Austin 1:8aa5cdb4ab67 86 *
Jonathan Austin 1:8aa5cdb4ab67 87 * @param pin the name of the pin for the pwm to target
Jonathan Austin 1:8aa5cdb4ab67 88 *
Jonathan Austin 1:8aa5cdb4ab67 89 * @param persistance the level of persistence for this pin PWM_PERSISTENCE_PERSISTENT (can not be replaced until freed, should only be used for system services really.)
Jonathan Austin 1:8aa5cdb4ab67 90 * or PWM_PERSISTENCE_TRANSIENT (can be replaced at any point if a channel is required.)
Jonathan Austin 1:8aa5cdb4ab67 91 */
Jonathan Austin 1:8aa5cdb4ab67 92 DynamicPwm::DynamicPwm(PinName pin, PwmPersistence persistence) : PwmOut(pin)
Jonathan Austin 1:8aa5cdb4ab67 93 {
Jonathan Austin 1:8aa5cdb4ab67 94 this->flags = persistence;
Jonathan Austin 1:8aa5cdb4ab67 95 }
Jonathan Austin 1:8aa5cdb4ab67 96
Jonathan Austin 1:8aa5cdb4ab67 97 /**
Jonathan Austin 1:8aa5cdb4ab67 98 * Redirects the pwm channel to point at a different pin.
Jonathan Austin 1:8aa5cdb4ab67 99 *
Jonathan Austin 1:8aa5cdb4ab67 100 * @param pin the desired pin to output a PWM wave.
Jonathan Austin 1:8aa5cdb4ab67 101 *
Jonathan Austin 1:8aa5cdb4ab67 102 * @code
Jonathan Austin 1:8aa5cdb4ab67 103 * DynamicPwm* pwm = DynamicPwm::allocate(PinName n);
Jonathan Austin 1:8aa5cdb4ab67 104 * pwm->redirect(p0); // pwm is now produced on p0
Jonathan Austin 1:8aa5cdb4ab67 105 * @endcode
Jonathan Austin 1:8aa5cdb4ab67 106 */
Jonathan Austin 1:8aa5cdb4ab67 107 void DynamicPwm::redirect(PinName pin)
Jonathan Austin 1:8aa5cdb4ab67 108 {
Jonathan Austin 1:8aa5cdb4ab67 109 gpiote_reinit(pin, _pwm.pin, (uint8_t)_pwm.pwm);
Jonathan Austin 1:8aa5cdb4ab67 110 this->_pwm.pin = pin;
Jonathan Austin 1:8aa5cdb4ab67 111 }
Jonathan Austin 1:8aa5cdb4ab67 112
Jonathan Austin 1:8aa5cdb4ab67 113 /**
Jonathan Austin 1:8aa5cdb4ab67 114 * Creates a new DynamicPwm instance, or reuses an existing instance that
Jonathan Austin 1:8aa5cdb4ab67 115 * has a persistence level of PWM_PERSISTENCE_TRANSIENT.
Jonathan Austin 1:8aa5cdb4ab67 116 *
Jonathan Austin 1:8aa5cdb4ab67 117 * @param pin the name of the pin for the pwm to target
Jonathan Austin 1:8aa5cdb4ab67 118 *
Jonathan Austin 1:8aa5cdb4ab67 119 * @param persistance the level of persistence for this pin PWM_PERSISTENCE_PERSISTENT (can not be replaced until freed, should only be used for system services really.)
Jonathan Austin 1:8aa5cdb4ab67 120 * or PWM_PERSISTENCE_TRANSIENT (can be replaced at any point if a channel is required.)
Jonathan Austin 1:8aa5cdb4ab67 121 *
Jonathan Austin 1:8aa5cdb4ab67 122 * @return a pointer to the first available free pwm channel - or the first one that can be reallocated. If
Jonathan Austin 1:8aa5cdb4ab67 123 * no channels are available, NULL is returned.
Jonathan Austin 1:8aa5cdb4ab67 124 *
Jonathan Austin 1:8aa5cdb4ab67 125 * @code
Jonathan Austin 1:8aa5cdb4ab67 126 * DynamicPwm* pwm = DynamicPwm::allocate(PinName n);
Jonathan Austin 1:8aa5cdb4ab67 127 * @endcode
Jonathan Austin 1:8aa5cdb4ab67 128 */
Jonathan Austin 1:8aa5cdb4ab67 129 DynamicPwm* DynamicPwm::allocate(PinName pin, PwmPersistence persistence)
Jonathan Austin 1:8aa5cdb4ab67 130 {
Jonathan Austin 1:8aa5cdb4ab67 131 //try to find a blank spot first
Jonathan Austin 1:8aa5cdb4ab67 132 for(int i = 0; i < NO_PWMS; i++)
Jonathan Austin 1:8aa5cdb4ab67 133 {
Jonathan Austin 1:8aa5cdb4ab67 134 if(pwms[i] == NULL)
Jonathan Austin 1:8aa5cdb4ab67 135 {
Jonathan Austin 1:8aa5cdb4ab67 136 lastUsed = i;
Jonathan Austin 1:8aa5cdb4ab67 137 pwms[i] = new DynamicPwm(pin, persistence);
Jonathan Austin 1:8aa5cdb4ab67 138 return pwms[i];
Jonathan Austin 1:8aa5cdb4ab67 139 }
Jonathan Austin 1:8aa5cdb4ab67 140 }
Jonathan Austin 1:8aa5cdb4ab67 141
Jonathan Austin 1:8aa5cdb4ab67 142 //no blank spot.. try to find a transient PWM
Jonathan Austin 1:8aa5cdb4ab67 143 int channelIterator = (lastUsed + 1 > NO_PWMS - 1) ? 0 : lastUsed + 1;
Jonathan Austin 1:8aa5cdb4ab67 144
Jonathan Austin 1:8aa5cdb4ab67 145 while(channelIterator != lastUsed)
Jonathan Austin 1:8aa5cdb4ab67 146 {
Jonathan Austin 1:8aa5cdb4ab67 147 if(pwms[channelIterator]->flags & PWM_PERSISTENCE_TRANSIENT)
Jonathan Austin 1:8aa5cdb4ab67 148 {
Jonathan Austin 1:8aa5cdb4ab67 149 lastUsed = channelIterator;
Jonathan Austin 1:8aa5cdb4ab67 150 pwms[channelIterator]->flags = persistence;
Jonathan Austin 1:8aa5cdb4ab67 151 pwms[channelIterator]->redirect(pin);
Jonathan Austin 1:8aa5cdb4ab67 152 return pwms[channelIterator];
Jonathan Austin 1:8aa5cdb4ab67 153 }
Jonathan Austin 1:8aa5cdb4ab67 154
Jonathan Austin 1:8aa5cdb4ab67 155 channelIterator = (channelIterator + 1 > NO_PWMS - 1) ? 0 : channelIterator + 1;
Jonathan Austin 1:8aa5cdb4ab67 156 }
Jonathan Austin 1:8aa5cdb4ab67 157
Jonathan Austin 1:8aa5cdb4ab67 158 //if we haven't found a free one, we must try to allocate the last used...
Jonathan Austin 1:8aa5cdb4ab67 159 if(pwms[lastUsed]->flags & PWM_PERSISTENCE_TRANSIENT)
Jonathan Austin 1:8aa5cdb4ab67 160 {
Jonathan Austin 1:8aa5cdb4ab67 161 pwms[lastUsed]->flags = persistence;
Jonathan Austin 1:8aa5cdb4ab67 162 pwms[lastUsed]->redirect(pin);
Jonathan Austin 1:8aa5cdb4ab67 163 return pwms[lastUsed];
Jonathan Austin 1:8aa5cdb4ab67 164 }
Jonathan Austin 1:8aa5cdb4ab67 165
Jonathan Austin 1:8aa5cdb4ab67 166 //well if we have no transient channels - we can't give any away! :( return null
Jonathan Austin 1:8aa5cdb4ab67 167 return (DynamicPwm*)NULL;
Jonathan Austin 1:8aa5cdb4ab67 168 }
Jonathan Austin 1:8aa5cdb4ab67 169
Jonathan Austin 1:8aa5cdb4ab67 170 /**
Jonathan Austin 1:8aa5cdb4ab67 171 * Frees this DynamicPwm instance for reuse.
Jonathan Austin 1:8aa5cdb4ab67 172 *
Jonathan Austin 1:8aa5cdb4ab67 173 * @code
Jonathan Austin 1:8aa5cdb4ab67 174 * DynamicPwm* pwm = DynamicPwm::allocate();
Jonathan Austin 1:8aa5cdb4ab67 175 * pwm->release();
Jonathan Austin 1:8aa5cdb4ab67 176 * @endcode
Jonathan Austin 1:8aa5cdb4ab67 177 */
Jonathan Austin 1:8aa5cdb4ab67 178 void DynamicPwm::release()
Jonathan Austin 1:8aa5cdb4ab67 179 {
Jonathan Austin 1:8aa5cdb4ab67 180 //free the pwm instance.
Jonathan Austin 1:8aa5cdb4ab67 181 NRF_GPIOTE->CONFIG[(uint8_t) _pwm.pwm] = 0;
Jonathan Austin 1:8aa5cdb4ab67 182 pwmout_free(&_pwm);
Jonathan Austin 1:8aa5cdb4ab67 183 this->flags = PWM_PERSISTENCE_TRANSIENT;
Jonathan Austin 1:8aa5cdb4ab67 184
Jonathan Austin 1:8aa5cdb4ab67 185 //set the pointer to this object to null...
Jonathan Austin 1:8aa5cdb4ab67 186 for(int i =0; i < NO_PWMS; i++)
Jonathan Austin 1:8aa5cdb4ab67 187 if(pwms[i] == this)
Jonathan Austin 1:8aa5cdb4ab67 188 {
Jonathan Austin 1:8aa5cdb4ab67 189 delete pwms[i];
Jonathan Austin 1:8aa5cdb4ab67 190 pwms[i] = NULL;
Jonathan Austin 1:8aa5cdb4ab67 191 }
Jonathan Austin 1:8aa5cdb4ab67 192 }
Jonathan Austin 1:8aa5cdb4ab67 193
Jonathan Austin 1:8aa5cdb4ab67 194 /**
Jonathan Austin 1:8aa5cdb4ab67 195 * A lightweight wrapper around the super class' write in order to capture the value
Jonathan Austin 1:8aa5cdb4ab67 196 *
Jonathan Austin 1:8aa5cdb4ab67 197 * @param value the duty cycle percentage in floating point format.
Jonathan Austin 1:8aa5cdb4ab67 198 *
Jonathan Austin 1:8aa5cdb4ab67 199 * @return MICROBIT_OK on success, MICROBIT_INVALID_PARAMETER if value is out of range
Jonathan Austin 1:8aa5cdb4ab67 200 *
Jonathan Austin 1:8aa5cdb4ab67 201 * @code
Jonathan Austin 1:8aa5cdb4ab67 202 * DynamicPwm* pwm = DynamicPwm::allocate();
Jonathan Austin 1:8aa5cdb4ab67 203 * pwm->write(0.5);
Jonathan Austin 1:8aa5cdb4ab67 204 * @endcode
Jonathan Austin 1:8aa5cdb4ab67 205 */
Jonathan Austin 1:8aa5cdb4ab67 206 int DynamicPwm::write(float value){
Jonathan Austin 1:8aa5cdb4ab67 207
Jonathan Austin 1:8aa5cdb4ab67 208 if(value < 0)
Jonathan Austin 1:8aa5cdb4ab67 209 return MICROBIT_INVALID_PARAMETER;
Jonathan Austin 1:8aa5cdb4ab67 210
Jonathan Austin 1:8aa5cdb4ab67 211 PwmOut::write(value);
Jonathan Austin 1:8aa5cdb4ab67 212 lastValue = value;
Jonathan Austin 1:8aa5cdb4ab67 213
Jonathan Austin 1:8aa5cdb4ab67 214 return MICROBIT_OK;
Jonathan Austin 1:8aa5cdb4ab67 215 }
Jonathan Austin 1:8aa5cdb4ab67 216
Jonathan Austin 1:8aa5cdb4ab67 217 /**
Jonathan Austin 1:8aa5cdb4ab67 218 * Retreives the PinName associated with this DynamicPwm instance.
Jonathan Austin 1:8aa5cdb4ab67 219 *
Jonathan Austin 1:8aa5cdb4ab67 220 * @code
Jonathan Austin 1:8aa5cdb4ab67 221 * DynamicPwm* pwm = DynamicPwm::allocate(PinName n);
Jonathan Austin 1:8aa5cdb4ab67 222 *
Jonathan Austin 1:8aa5cdb4ab67 223 * // returns the PinName n.
Jonathan Austin 1:8aa5cdb4ab67 224 * pwm->getPinName();
Jonathan Austin 1:8aa5cdb4ab67 225 * @endcode
Jonathan Austin 1:8aa5cdb4ab67 226 *
Jonathan Austin 1:8aa5cdb4ab67 227 * @note This should be used to check that the DynamicPwm instance has not
Jonathan Austin 1:8aa5cdb4ab67 228 * been reallocated for use in another part of a program.
Jonathan Austin 1:8aa5cdb4ab67 229 */
Jonathan Austin 1:8aa5cdb4ab67 230 PinName DynamicPwm::getPinName()
Jonathan Austin 1:8aa5cdb4ab67 231 {
Jonathan Austin 1:8aa5cdb4ab67 232 return _pwm.pin;
Jonathan Austin 1:8aa5cdb4ab67 233 }
Jonathan Austin 1:8aa5cdb4ab67 234
Jonathan Austin 1:8aa5cdb4ab67 235 /**
Jonathan Austin 1:8aa5cdb4ab67 236 * Retreives the last value that has been written to this DynamicPwm instance.
Jonathan Austin 1:8aa5cdb4ab67 237 * in the range 0 - 1023 inclusive.
Jonathan Austin 1:8aa5cdb4ab67 238 *
Jonathan Austin 1:8aa5cdb4ab67 239 * @code
Jonathan Austin 1:8aa5cdb4ab67 240 * DynamicPwm* pwm = DynamicPwm::allocate(PinName n);
Jonathan Austin 1:8aa5cdb4ab67 241 * pwm->write(0.5);
Jonathan Austin 1:8aa5cdb4ab67 242 *
Jonathan Austin 1:8aa5cdb4ab67 243 * // will return 512.
Jonathan Austin 1:8aa5cdb4ab67 244 * pwm->getValue();
Jonathan Austin 1:8aa5cdb4ab67 245 * @endcode
Jonathan Austin 1:8aa5cdb4ab67 246 */
Jonathan Austin 1:8aa5cdb4ab67 247 int DynamicPwm::getValue()
Jonathan Austin 1:8aa5cdb4ab67 248 {
Jonathan Austin 1:8aa5cdb4ab67 249 return (float)lastValue * float(MICROBIT_PIN_MAX_OUTPUT);
Jonathan Austin 1:8aa5cdb4ab67 250 }
Jonathan Austin 1:8aa5cdb4ab67 251
Jonathan Austin 1:8aa5cdb4ab67 252 /**
Jonathan Austin 1:8aa5cdb4ab67 253 * Retreives the current period in use by the entire PWM module in microseconds.
Jonathan Austin 1:8aa5cdb4ab67 254 *
Jonathan Austin 1:8aa5cdb4ab67 255 * Example:
Jonathan Austin 1:8aa5cdb4ab67 256 * @code
Jonathan Austin 1:8aa5cdb4ab67 257 * DynamicPwm* pwm = DynamicPwm::allocate(PinName n);
Jonathan Austin 1:8aa5cdb4ab67 258 * pwm->getPeriod();
Jonathan Austin 1:8aa5cdb4ab67 259 * @endcode
Jonathan Austin 1:8aa5cdb4ab67 260 */
Jonathan Austin 1:8aa5cdb4ab67 261 int DynamicPwm::getPeriodUs()
Jonathan Austin 1:8aa5cdb4ab67 262 {
Jonathan Austin 1:8aa5cdb4ab67 263 return sharedPeriod;
Jonathan Austin 1:8aa5cdb4ab67 264 }
Jonathan Austin 1:8aa5cdb4ab67 265
Jonathan Austin 1:8aa5cdb4ab67 266 /**
Jonathan Austin 1:8aa5cdb4ab67 267 * Retreives the current period in use by the entire PWM module in milliseconds.
Jonathan Austin 1:8aa5cdb4ab67 268 *
Jonathan Austin 1:8aa5cdb4ab67 269 * Example:
Jonathan Austin 1:8aa5cdb4ab67 270 * @code
Jonathan Austin 1:8aa5cdb4ab67 271 * DynamicPwm* pwm = DynamicPwm::allocate(PinName n);
Jonathan Austin 1:8aa5cdb4ab67 272 * pwm->setPeriodUs(20000);
Jonathan Austin 1:8aa5cdb4ab67 273 *
Jonathan Austin 1:8aa5cdb4ab67 274 * // will return 20000
Jonathan Austin 1:8aa5cdb4ab67 275 * pwm->getPeriod();
Jonathan Austin 1:8aa5cdb4ab67 276 * @endcode
Jonathan Austin 1:8aa5cdb4ab67 277 */
Jonathan Austin 1:8aa5cdb4ab67 278 int DynamicPwm::getPeriod()
Jonathan Austin 1:8aa5cdb4ab67 279 {
Jonathan Austin 1:8aa5cdb4ab67 280 return getPeriodUs() / 1000;
Jonathan Austin 1:8aa5cdb4ab67 281 }
Jonathan Austin 1:8aa5cdb4ab67 282
Jonathan Austin 1:8aa5cdb4ab67 283 /**
Jonathan Austin 1:8aa5cdb4ab67 284 * Sets the period used by the WHOLE PWM module.
Jonathan Austin 1:8aa5cdb4ab67 285 *
Jonathan Austin 1:8aa5cdb4ab67 286 * @param period the desired period in microseconds.
Jonathan Austin 1:8aa5cdb4ab67 287 *
Jonathan Austin 1:8aa5cdb4ab67 288 * @return MICROBIT_OK on success, MICROBIT_INVALID_PARAMETER if period is out of range
Jonathan Austin 1:8aa5cdb4ab67 289 *
Jonathan Austin 1:8aa5cdb4ab67 290 * Example:
Jonathan Austin 1:8aa5cdb4ab67 291 * @code
Jonathan Austin 1:8aa5cdb4ab67 292 * DynamicPwm* pwm = DynamicPwm::allocate(PinName n);
Jonathan Austin 1:8aa5cdb4ab67 293 *
Jonathan Austin 1:8aa5cdb4ab67 294 * // period now is 20ms
Jonathan Austin 1:8aa5cdb4ab67 295 * pwm->setPeriodUs(20000);
Jonathan Austin 1:8aa5cdb4ab67 296 * @endcode
Jonathan Austin 1:8aa5cdb4ab67 297 *
Jonathan Austin 1:8aa5cdb4ab67 298 * @note Any changes to the period will AFFECT ALL CHANNELS.
Jonathan Austin 1:8aa5cdb4ab67 299 */
Jonathan Austin 1:8aa5cdb4ab67 300 int DynamicPwm::setPeriodUs(int period)
Jonathan Austin 1:8aa5cdb4ab67 301 {
Jonathan Austin 1:8aa5cdb4ab67 302 if(period < 0)
Jonathan Austin 1:8aa5cdb4ab67 303 return MICROBIT_INVALID_PARAMETER;
Jonathan Austin 1:8aa5cdb4ab67 304
Jonathan Austin 1:8aa5cdb4ab67 305 //#HACK this forces mbed to update the pulse width calculation.
Jonathan Austin 1:8aa5cdb4ab67 306 period_us(period);
Jonathan Austin 1:8aa5cdb4ab67 307 write(lastValue);
Jonathan Austin 1:8aa5cdb4ab67 308 sharedPeriod = period;
Jonathan Austin 1:8aa5cdb4ab67 309
Jonathan Austin 1:8aa5cdb4ab67 310 return MICROBIT_OK;
Jonathan Austin 1:8aa5cdb4ab67 311 }
Jonathan Austin 1:8aa5cdb4ab67 312
Jonathan Austin 1:8aa5cdb4ab67 313 /**
Jonathan Austin 1:8aa5cdb4ab67 314 * Sets the period used by the WHOLE PWM module. Any changes to the period will AFFECT ALL CHANNELS.
Jonathan Austin 1:8aa5cdb4ab67 315 *
Jonathan Austin 1:8aa5cdb4ab67 316 * @param period the desired period in milliseconds.
Jonathan Austin 1:8aa5cdb4ab67 317 *
Jonathan Austin 1:8aa5cdb4ab67 318 * @return MICROBIT_OK on success, MICROBIT_INVALID_PARAMETER if period is out of range
Jonathan Austin 1:8aa5cdb4ab67 319 *
Jonathan Austin 1:8aa5cdb4ab67 320 * Example:
Jonathan Austin 1:8aa5cdb4ab67 321 * @code
Jonathan Austin 1:8aa5cdb4ab67 322 * DynamicPwm* pwm = DynamicPwm::allocate(PinName n);
Jonathan Austin 1:8aa5cdb4ab67 323 *
Jonathan Austin 1:8aa5cdb4ab67 324 * // period now is 20ms
Jonathan Austin 1:8aa5cdb4ab67 325 * pwm->setPeriod(20);
Jonathan Austin 1:8aa5cdb4ab67 326 * @endcode
Jonathan Austin 1:8aa5cdb4ab67 327 */
Jonathan Austin 1:8aa5cdb4ab67 328 int DynamicPwm::setPeriod(int period)
Jonathan Austin 1:8aa5cdb4ab67 329 {
Jonathan Austin 1:8aa5cdb4ab67 330 return setPeriodUs(period * 1000);
LancasterUniversity 3:d86a4ddc1867 331 }