Lancaster University
mbed.org local branch of microbit-dal. The real version lives in git at https://github.com/lancaster-university/microbit-dal
Dependencies: BLE_API nRF51822 mbed-dev-bin
Dependents: microbit Microbit IoTChallenge1 microbit ... more
inc/drivers/DynamicPwm.h@1:8aa5cdb4ab67, 2016-04-07 (annotated)
- Committer:
- Jonathan Austin
- Date:
- Thu Apr 07 01:33:22 2016 +0100
- Revision:
- 1:8aa5cdb4ab67
Synchronized with git rev 55cb9199
Who changed what in which revision?
| User | Revision | Line number | New 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 | #include "mbed.h" |
| Jonathan Austin |
1:8aa5cdb4ab67 | 27 | #include "MicroBitConfig.h" |
| Jonathan Austin |
1:8aa5cdb4ab67 | 28 | |
| Jonathan Austin |
1:8aa5cdb4ab67 | 29 | #ifndef MICROBIT_DYNAMIC_PWM_H |
| Jonathan Austin |
1:8aa5cdb4ab67 | 30 | #define MICROBIT_DYNAMIC_PWM_H |
| Jonathan Austin |
1:8aa5cdb4ab67 | 31 | |
| Jonathan Austin |
1:8aa5cdb4ab67 | 32 | #define NO_PWMS 3 |
| Jonathan Austin |
1:8aa5cdb4ab67 | 33 | #define MICROBIT_DEFAULT_PWM_PERIOD 20000 |
| Jonathan Austin |
1:8aa5cdb4ab67 | 34 | |
| Jonathan Austin |
1:8aa5cdb4ab67 | 35 | enum PwmPersistence |
| Jonathan Austin |
1:8aa5cdb4ab67 | 36 | { |
| Jonathan Austin |
1:8aa5cdb4ab67 | 37 | PWM_PERSISTENCE_TRANSIENT = 1, |
| Jonathan Austin |
1:8aa5cdb4ab67 | 38 | PWM_PERSISTENCE_PERSISTENT = 2, |
| Jonathan Austin |
1:8aa5cdb4ab67 | 39 | }; |
| Jonathan Austin |
1:8aa5cdb4ab67 | 40 | |
| Jonathan Austin |
1:8aa5cdb4ab67 | 41 | /** |
| Jonathan Austin |
1:8aa5cdb4ab67 | 42 | * Class definition for DynamicPwm. |
| Jonathan Austin |
1:8aa5cdb4ab67 | 43 | * |
| Jonathan Austin |
1:8aa5cdb4ab67 | 44 | * This class addresses a few issues found in the underlying libraries. |
| Jonathan Austin |
1:8aa5cdb4ab67 | 45 | * This provides the ability for a neat, clean swap between PWM channels. |
| Jonathan Austin |
1:8aa5cdb4ab67 | 46 | */ |
| Jonathan Austin |
1:8aa5cdb4ab67 | 47 | class DynamicPwm : public PwmOut |
| Jonathan Austin |
1:8aa5cdb4ab67 | 48 | { |
| Jonathan Austin |
1:8aa5cdb4ab67 | 49 | private: |
| Jonathan Austin |
1:8aa5cdb4ab67 | 50 | static DynamicPwm* pwms[NO_PWMS]; |
| Jonathan Austin |
1:8aa5cdb4ab67 | 51 | static uint8_t lastUsed; |
| Jonathan Austin |
1:8aa5cdb4ab67 | 52 | static uint16_t sharedPeriod; |
| Jonathan Austin |
1:8aa5cdb4ab67 | 53 | uint8_t flags; |
| Jonathan Austin |
1:8aa5cdb4ab67 | 54 | float lastValue; |
| Jonathan Austin |
1:8aa5cdb4ab67 | 55 | |
| Jonathan Austin |
1:8aa5cdb4ab67 | 56 | |
| Jonathan Austin |
1:8aa5cdb4ab67 | 57 | |
| Jonathan Austin |
1:8aa5cdb4ab67 | 58 | /** |
| Jonathan Austin |
1:8aa5cdb4ab67 | 59 | * An internal constructor used when allocating a new DynamicPwm instance. |
| Jonathan Austin |
1:8aa5cdb4ab67 | 60 | * |
| Jonathan Austin |
1:8aa5cdb4ab67 | 61 | * @param pin the name of the pin for the pwm to target |
| Jonathan Austin |
1:8aa5cdb4ab67 | 62 | * |
| Jonathan Austin |
1:8aa5cdb4ab67 | 63 | * @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 | 64 | * or PWM_PERSISTENCE_TRANSIENT (can be replaced at any point if a channel is required.) |
| Jonathan Austin |
1:8aa5cdb4ab67 | 65 | */ |
| Jonathan Austin |
1:8aa5cdb4ab67 | 66 | DynamicPwm(PinName pin, PwmPersistence persistence = PWM_PERSISTENCE_TRANSIENT); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 67 | |
| Jonathan Austin |
1:8aa5cdb4ab67 | 68 | public: |
| Jonathan Austin |
1:8aa5cdb4ab67 | 69 | |
| Jonathan Austin |
1:8aa5cdb4ab67 | 70 | /** |
| Jonathan Austin |
1:8aa5cdb4ab67 | 71 | * Redirects the pwm channel to point at a different pin. |
| Jonathan Austin |
1:8aa5cdb4ab67 | 72 | * |
| Jonathan Austin |
1:8aa5cdb4ab67 | 73 | * @param pin the desired pin to output a PWM wave. |
| Jonathan Austin |
1:8aa5cdb4ab67 | 74 | * |
| Jonathan Austin |
1:8aa5cdb4ab67 | 75 | * @code |
| Jonathan Austin |
1:8aa5cdb4ab67 | 76 | * DynamicPwm* pwm = DynamicPwm::allocate(PinName n); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 77 | * pwm->redirect(p0); // pwm is now produced on p0 |
| Jonathan Austin |
1:8aa5cdb4ab67 | 78 | * @endcode |
| Jonathan Austin |
1:8aa5cdb4ab67 | 79 | */ |
| Jonathan Austin |
1:8aa5cdb4ab67 | 80 | void redirect(PinName pin); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 81 | |
| Jonathan Austin |
1:8aa5cdb4ab67 | 82 | |
| Jonathan Austin |
1:8aa5cdb4ab67 | 83 | /** |
| Jonathan Austin |
1:8aa5cdb4ab67 | 84 | * Creates a new DynamicPwm instance, or reuses an existing instance that |
| Jonathan Austin |
1:8aa5cdb4ab67 | 85 | * has a persistence level of PWM_PERSISTENCE_TRANSIENT. |
| 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 | * @return a pointer to the first available free pwm channel - or the first one that can be reallocated. If |
| Jonathan Austin |
1:8aa5cdb4ab67 | 93 | * no channels are available, NULL is returned. |
| Jonathan Austin |
1:8aa5cdb4ab67 | 94 | * |
| Jonathan Austin |
1:8aa5cdb4ab67 | 95 | * @code |
| Jonathan Austin |
1:8aa5cdb4ab67 | 96 | * DynamicPwm* pwm = DynamicPwm::allocate(PinName n); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 97 | * @endcode |
| Jonathan Austin |
1:8aa5cdb4ab67 | 98 | */ |
| Jonathan Austin |
1:8aa5cdb4ab67 | 99 | static DynamicPwm* allocate(PinName pin, PwmPersistence persistence = PWM_PERSISTENCE_TRANSIENT); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 100 | |
| Jonathan Austin |
1:8aa5cdb4ab67 | 101 | /** |
| Jonathan Austin |
1:8aa5cdb4ab67 | 102 | * Frees this DynamicPwm instance for reuse. |
| Jonathan Austin |
1:8aa5cdb4ab67 | 103 | * |
| Jonathan Austin |
1:8aa5cdb4ab67 | 104 | * @code |
| Jonathan Austin |
1:8aa5cdb4ab67 | 105 | * DynamicPwm* pwm = DynamicPwm::allocate(); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 106 | * pwm->release(); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 107 | * @endcode |
| Jonathan Austin |
1:8aa5cdb4ab67 | 108 | */ |
| Jonathan Austin |
1:8aa5cdb4ab67 | 109 | void release(); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 110 | |
| Jonathan Austin |
1:8aa5cdb4ab67 | 111 | /** |
| Jonathan Austin |
1:8aa5cdb4ab67 | 112 | * A lightweight wrapper around the super class' write in order to capture the value |
| Jonathan Austin |
1:8aa5cdb4ab67 | 113 | * |
| Jonathan Austin |
1:8aa5cdb4ab67 | 114 | * @param value the duty cycle percentage in floating point format. |
| Jonathan Austin |
1:8aa5cdb4ab67 | 115 | * |
| Jonathan Austin |
1:8aa5cdb4ab67 | 116 | * @return MICROBIT_OK on success, MICROBIT_INVALID_PARAMETER if value is out of range |
| Jonathan Austin |
1:8aa5cdb4ab67 | 117 | * |
| Jonathan Austin |
1:8aa5cdb4ab67 | 118 | * @code |
| Jonathan Austin |
1:8aa5cdb4ab67 | 119 | * DynamicPwm* pwm = DynamicPwm::allocate(); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 120 | * pwm->write(0.5); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 121 | * @endcode |
| Jonathan Austin |
1:8aa5cdb4ab67 | 122 | */ |
| Jonathan Austin |
1:8aa5cdb4ab67 | 123 | int write(float value); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 124 | |
| Jonathan Austin |
1:8aa5cdb4ab67 | 125 | /** |
| Jonathan Austin |
1:8aa5cdb4ab67 | 126 | * Retreives the PinName associated with this DynamicPwm instance. |
| Jonathan Austin |
1:8aa5cdb4ab67 | 127 | * |
| Jonathan Austin |
1:8aa5cdb4ab67 | 128 | * @code |
| Jonathan Austin |
1:8aa5cdb4ab67 | 129 | * DynamicPwm* pwm = DynamicPwm::allocate(PinName n); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 130 | * |
| Jonathan Austin |
1:8aa5cdb4ab67 | 131 | * // returns the PinName n. |
| Jonathan Austin |
1:8aa5cdb4ab67 | 132 | * pwm->getPinName(); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 133 | * @endcode |
| Jonathan Austin |
1:8aa5cdb4ab67 | 134 | * |
| Jonathan Austin |
1:8aa5cdb4ab67 | 135 | * @note This should be used to check that the DynamicPwm instance has not |
| Jonathan Austin |
1:8aa5cdb4ab67 | 136 | * been reallocated for use in another part of a program. |
| Jonathan Austin |
1:8aa5cdb4ab67 | 137 | */ |
| Jonathan Austin |
1:8aa5cdb4ab67 | 138 | PinName getPinName(); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 139 | |
| Jonathan Austin |
1:8aa5cdb4ab67 | 140 | /** |
| Jonathan Austin |
1:8aa5cdb4ab67 | 141 | * Retreives the last value that has been written to this DynamicPwm instance. |
| Jonathan Austin |
1:8aa5cdb4ab67 | 142 | * in the range 0 - 1023 inclusive. |
| Jonathan Austin |
1:8aa5cdb4ab67 | 143 | * |
| Jonathan Austin |
1:8aa5cdb4ab67 | 144 | * @code |
| Jonathan Austin |
1:8aa5cdb4ab67 | 145 | * DynamicPwm* pwm = DynamicPwm::allocate(PinName n); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 146 | * pwm->write(0.5); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 147 | * |
| Jonathan Austin |
1:8aa5cdb4ab67 | 148 | * // will return 512. |
| Jonathan Austin |
1:8aa5cdb4ab67 | 149 | * pwm->getValue(); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 150 | * @endcode |
| Jonathan Austin |
1:8aa5cdb4ab67 | 151 | */ |
| Jonathan Austin |
1:8aa5cdb4ab67 | 152 | int getValue(); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 153 | |
| Jonathan Austin |
1:8aa5cdb4ab67 | 154 | /** |
| Jonathan Austin |
1:8aa5cdb4ab67 | 155 | * Retreives the current period in use by the entire PWM module in microseconds. |
| Jonathan Austin |
1:8aa5cdb4ab67 | 156 | * |
| Jonathan Austin |
1:8aa5cdb4ab67 | 157 | * Example: |
| Jonathan Austin |
1:8aa5cdb4ab67 | 158 | * @code |
| Jonathan Austin |
1:8aa5cdb4ab67 | 159 | * DynamicPwm* pwm = DynamicPwm::allocate(PinName n); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 160 | * pwm->getPeriod(); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 161 | * @endcode |
| Jonathan Austin |
1:8aa5cdb4ab67 | 162 | */ |
| Jonathan Austin |
1:8aa5cdb4ab67 | 163 | int getPeriodUs(); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 164 | |
| Jonathan Austin |
1:8aa5cdb4ab67 | 165 | /** |
| Jonathan Austin |
1:8aa5cdb4ab67 | 166 | * Retreives the current period in use by the entire PWM module in milliseconds. |
| Jonathan Austin |
1:8aa5cdb4ab67 | 167 | * |
| Jonathan Austin |
1:8aa5cdb4ab67 | 168 | * Example: |
| Jonathan Austin |
1:8aa5cdb4ab67 | 169 | * @code |
| Jonathan Austin |
1:8aa5cdb4ab67 | 170 | * DynamicPwm* pwm = DynamicPwm::allocate(PinName n); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 171 | * pwm->setPeriodUs(20000); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 172 | * |
| Jonathan Austin |
1:8aa5cdb4ab67 | 173 | * // will return 20000 |
| Jonathan Austin |
1:8aa5cdb4ab67 | 174 | * pwm->getPeriod(); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 175 | * @endcode |
| Jonathan Austin |
1:8aa5cdb4ab67 | 176 | */ |
| Jonathan Austin |
1:8aa5cdb4ab67 | 177 | int getPeriod(); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 178 | |
| Jonathan Austin |
1:8aa5cdb4ab67 | 179 | /** |
| Jonathan Austin |
1:8aa5cdb4ab67 | 180 | * Sets the period used by the WHOLE PWM module. |
| Jonathan Austin |
1:8aa5cdb4ab67 | 181 | * |
| Jonathan Austin |
1:8aa5cdb4ab67 | 182 | * @param period the desired period in microseconds. |
| Jonathan Austin |
1:8aa5cdb4ab67 | 183 | * |
| Jonathan Austin |
1:8aa5cdb4ab67 | 184 | * @return MICROBIT_OK on success, MICROBIT_INVALID_PARAMETER if period is out of range |
| Jonathan Austin |
1:8aa5cdb4ab67 | 185 | * |
| Jonathan Austin |
1:8aa5cdb4ab67 | 186 | * Example: |
| Jonathan Austin |
1:8aa5cdb4ab67 | 187 | * @code |
| Jonathan Austin |
1:8aa5cdb4ab67 | 188 | * DynamicPwm* pwm = DynamicPwm::allocate(PinName n); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 189 | * |
| Jonathan Austin |
1:8aa5cdb4ab67 | 190 | * // period now is 20ms |
| Jonathan Austin |
1:8aa5cdb4ab67 | 191 | * pwm->setPeriodUs(20000); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 192 | * @endcode |
| Jonathan Austin |
1:8aa5cdb4ab67 | 193 | * |
| Jonathan Austin |
1:8aa5cdb4ab67 | 194 | * @note Any changes to the period will AFFECT ALL CHANNELS. |
| Jonathan Austin |
1:8aa5cdb4ab67 | 195 | */ |
| Jonathan Austin |
1:8aa5cdb4ab67 | 196 | int setPeriodUs(int period); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 197 | |
| Jonathan Austin |
1:8aa5cdb4ab67 | 198 | /** |
| Jonathan Austin |
1:8aa5cdb4ab67 | 199 | * Sets the period used by the WHOLE PWM module. Any changes to the period will AFFECT ALL CHANNELS. |
| Jonathan Austin |
1:8aa5cdb4ab67 | 200 | * |
| Jonathan Austin |
1:8aa5cdb4ab67 | 201 | * @param period the desired period in milliseconds. |
| Jonathan Austin |
1:8aa5cdb4ab67 | 202 | * |
| Jonathan Austin |
1:8aa5cdb4ab67 | 203 | * @return MICROBIT_OK on success, MICROBIT_INVALID_PARAMETER if period is out of range |
| Jonathan Austin |
1:8aa5cdb4ab67 | 204 | * |
| Jonathan Austin |
1:8aa5cdb4ab67 | 205 | * Example: |
| Jonathan Austin |
1:8aa5cdb4ab67 | 206 | * @code |
| Jonathan Austin |
1:8aa5cdb4ab67 | 207 | * DynamicPwm* pwm = DynamicPwm::allocate(PinName n); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 208 | * |
| Jonathan Austin |
1:8aa5cdb4ab67 | 209 | * // period now is 20ms |
| Jonathan Austin |
1:8aa5cdb4ab67 | 210 | * pwm->setPeriod(20); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 211 | * @endcode |
| Jonathan Austin |
1:8aa5cdb4ab67 | 212 | */ |
| Jonathan Austin |
1:8aa5cdb4ab67 | 213 | int setPeriod(int period); |
| Jonathan Austin |
1:8aa5cdb4ab67 | 214 | }; |
| Jonathan Austin |
1:8aa5cdb4ab67 | 215 | |
| Jonathan Austin |
1:8aa5cdb4ab67 | 216 | #endif |