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api/PwmOut.h@10:3bc89ef62ce7, 2013-06-14 (annotated)

Committer:
emilmont
Date:
Fri Jun 14 17:49:17 2013 +0100
Revision:
10:3bc89ef62ce7
Parent:
9:0ce32e54c9a7
Child:
13:0645d8841f51
Unify mbed library sources

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emilmont 10:3bc89ef62ce7 1 /* mbed Microcontroller Library
emilmont 10:3bc89ef62ce7 2 * Copyright (c) 2006-2013 ARM Limited
emilmont 10:3bc89ef62ce7 3 *
emilmont 10:3bc89ef62ce7 4 * Licensed under the Apache License, Version 2.0 (the "License");
emilmont 10:3bc89ef62ce7 5 * you may not use this file except in compliance with the License.
emilmont 10:3bc89ef62ce7 6 * You may obtain a copy of the License at
emilmont 10:3bc89ef62ce7 7 *
emilmont 10:3bc89ef62ce7 8 * http://www.apache.org/licenses/LICENSE-2.0
emilmont 10:3bc89ef62ce7 9 *
emilmont 10:3bc89ef62ce7 10 * Unless required by applicable law or agreed to in writing, software
emilmont 10:3bc89ef62ce7 11 * distributed under the License is distributed on an "AS IS" BASIS,
emilmont 10:3bc89ef62ce7 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
emilmont 10:3bc89ef62ce7 13 * See the License for the specific language governing permissions and
emilmont 10:3bc89ef62ce7 14 * limitations under the License.
emilmont 10:3bc89ef62ce7 15 */
emilmont 10:3bc89ef62ce7 16 #ifndef MBED_PWMOUT_H
emilmont 10:3bc89ef62ce7 17 #define MBED_PWMOUT_H
emilmont 10:3bc89ef62ce7 18
emilmont 10:3bc89ef62ce7 19 #include "platform.h"
emilmont 10:3bc89ef62ce7 20
emilmont 10:3bc89ef62ce7 21 #if DEVICE_PWMOUT
emilmont 10:3bc89ef62ce7 22 #include "pwmout_api.h"
emilmont 10:3bc89ef62ce7 23
emilmont 10:3bc89ef62ce7 24 namespace mbed {
emilmont 10:3bc89ef62ce7 25
emilmont 10:3bc89ef62ce7 26 /** A pulse-width modulation digital output
emilmont 10:3bc89ef62ce7 27 *
emilmont 10:3bc89ef62ce7 28 * Example
emilmont 10:3bc89ef62ce7 29 * @code
emilmont 10:3bc89ef62ce7 30 * // Fade a led on.
emilmont 10:3bc89ef62ce7 31 * #include "mbed.h"
emilmont 10:3bc89ef62ce7 32 *
emilmont 10:3bc89ef62ce7 33 * PwmOut led(LED1);
emilmont 10:3bc89ef62ce7 34 *
emilmont 10:3bc89ef62ce7 35 * int main() {
emilmont 10:3bc89ef62ce7 36 * while(1) {
emilmont 10:3bc89ef62ce7 37 * led = led + 0.01;
emilmont 10:3bc89ef62ce7 38 * wait(0.2);
emilmont 10:3bc89ef62ce7 39 * if(led == 1.0) {
emilmont 10:3bc89ef62ce7 40 * led = 0;
emilmont 10:3bc89ef62ce7 41 * }
emilmont 10:3bc89ef62ce7 42 * }
emilmont 10:3bc89ef62ce7 43 * }
emilmont 10:3bc89ef62ce7 44 * @endcode
emilmont 10:3bc89ef62ce7 45 *
emilmont 10:3bc89ef62ce7 46 * @note
emilmont 10:3bc89ef62ce7 47 * On the LPC1768 and LPC2368, the PWMs all share the same
emilmont 10:3bc89ef62ce7 48 * period - if you change the period for one, you change it for all.
emilmont 10:3bc89ef62ce7 49 * Although routines that change the period maintain the duty cycle
emilmont 10:3bc89ef62ce7 50 * for its PWM, all other PWMs will require their duty cycle to be
emilmont 10:3bc89ef62ce7 51 * refreshed.
emilmont 10:3bc89ef62ce7 52 */
emilmont 10:3bc89ef62ce7 53 class PwmOut {
emilmont 10:3bc89ef62ce7 54
emilmont 10:3bc89ef62ce7 55 public:
emilmont 10:3bc89ef62ce7 56
emilmont 10:3bc89ef62ce7 57 /** Create a PwmOut connected to the specified pin
emilmont 10:3bc89ef62ce7 58 *
emilmont 10:3bc89ef62ce7 59 * @param pin PwmOut pin to connect to
emilmont 10:3bc89ef62ce7 60 */
emilmont 10:3bc89ef62ce7 61 PwmOut(PinName pin) {
emilmont 10:3bc89ef62ce7 62 pwmout_init(&_pwm, pin);
emilmont 10:3bc89ef62ce7 63 }
emilmont 10:3bc89ef62ce7 64
emilmont 10:3bc89ef62ce7 65 /** Set the ouput duty-cycle, specified as a percentage (float)
emilmont 10:3bc89ef62ce7 66 *
emilmont 10:3bc89ef62ce7 67 * @param value A floating-point value representing the output duty-cycle,
emilmont 10:3bc89ef62ce7 68 * specified as a percentage. The value should lie between
emilmont 10:3bc89ef62ce7 69 * 0.0f (representing on 0%) and 1.0f (representing on 100%).
emilmont 10:3bc89ef62ce7 70 * Values outside this range will be saturated to 0.0f or 1.0f.
emilmont 10:3bc89ef62ce7 71 */
emilmont 10:3bc89ef62ce7 72 void write(float value) {
emilmont 10:3bc89ef62ce7 73 pwmout_write(&_pwm, value);
emilmont 10:3bc89ef62ce7 74 }
emilmont 10:3bc89ef62ce7 75
emilmont 10:3bc89ef62ce7 76 /** Return the current output duty-cycle setting, measured as a percentage (float)
emilmont 10:3bc89ef62ce7 77 *
emilmont 10:3bc89ef62ce7 78 * @returns
emilmont 10:3bc89ef62ce7 79 * A floating-point value representing the current duty-cycle being output on the pin,
emilmont 10:3bc89ef62ce7 80 * measured as a percentage. The returned value will lie between
emilmont 10:3bc89ef62ce7 81 * 0.0f (representing on 0%) and 1.0f (representing on 100%).
emilmont 10:3bc89ef62ce7 82 *
emilmont 10:3bc89ef62ce7 83 * @note
emilmont 10:3bc89ef62ce7 84 * This value may not match exactly the value set by a previous <write>.
emilmont 10:3bc89ef62ce7 85 */
emilmont 10:3bc89ef62ce7 86 float read() {
emilmont 10:3bc89ef62ce7 87 return pwmout_read(&_pwm);
emilmont 10:3bc89ef62ce7 88 }
emilmont 10:3bc89ef62ce7 89
emilmont 10:3bc89ef62ce7 90 /** Set the PWM period, specified in seconds (float), keeping the duty cycle the same.
emilmont 10:3bc89ef62ce7 91 *
emilmont 10:3bc89ef62ce7 92 * @note
emilmont 10:3bc89ef62ce7 93 * The resolution is currently in microseconds; periods smaller than this
emilmont 10:3bc89ef62ce7 94 * will be set to zero.
emilmont 10:3bc89ef62ce7 95 */
emilmont 10:3bc89ef62ce7 96 void period(float seconds) {
emilmont 10:3bc89ef62ce7 97 pwmout_period(&_pwm, seconds);
emilmont 10:3bc89ef62ce7 98 }
emilmont 10:3bc89ef62ce7 99
emilmont 10:3bc89ef62ce7 100 /** Set the PWM period, specified in milli-seconds (int), keeping the duty cycle the same.
emilmont 10:3bc89ef62ce7 101 */
emilmont 10:3bc89ef62ce7 102 void period_ms(int ms) {
emilmont 10:3bc89ef62ce7 103 pwmout_period_ms(&_pwm, ms);
emilmont 10:3bc89ef62ce7 104 }
emilmont 10:3bc89ef62ce7 105
emilmont 10:3bc89ef62ce7 106 /** Set the PWM period, specified in micro-seconds (int), keeping the duty cycle the same.
emilmont 10:3bc89ef62ce7 107 */
emilmont 10:3bc89ef62ce7 108 void period_us(int us) {
emilmont 10:3bc89ef62ce7 109 pwmout_period_us(&_pwm, us);
emilmont 10:3bc89ef62ce7 110 }
emilmont 10:3bc89ef62ce7 111
emilmont 10:3bc89ef62ce7 112 /** Set the PWM pulsewidth, specified in seconds (float), keeping the period the same.
emilmont 10:3bc89ef62ce7 113 */
emilmont 10:3bc89ef62ce7 114 void pulsewidth(float seconds) {
emilmont 10:3bc89ef62ce7 115 pwmout_pulsewidth(&_pwm, seconds);
emilmont 10:3bc89ef62ce7 116 }
emilmont 10:3bc89ef62ce7 117
emilmont 10:3bc89ef62ce7 118 /** Set the PWM pulsewidth, specified in milli-seconds (int), keeping the period the same.
emilmont 10:3bc89ef62ce7 119 */
emilmont 10:3bc89ef62ce7 120 void pulsewidth_ms(int ms) {
emilmont 10:3bc89ef62ce7 121 pwmout_pulsewidth_ms(&_pwm, ms);
emilmont 10:3bc89ef62ce7 122 }
emilmont 10:3bc89ef62ce7 123
emilmont 10:3bc89ef62ce7 124 /** Set the PWM pulsewidth, specified in micro-seconds (int), keeping the period the same.
emilmont 10:3bc89ef62ce7 125 */
emilmont 10:3bc89ef62ce7 126 void pulsewidth_us(int us) {
emilmont 10:3bc89ef62ce7 127 pwmout_pulsewidth_us(&_pwm, us);
emilmont 10:3bc89ef62ce7 128 }
emilmont 10:3bc89ef62ce7 129
emilmont 10:3bc89ef62ce7 130 #ifdef MBED_OPERATORS
emilmont 10:3bc89ef62ce7 131 /** A operator shorthand for write()
emilmont 10:3bc89ef62ce7 132 */
emilmont 10:3bc89ef62ce7 133 PwmOut& operator= (float value) {
emilmont 10:3bc89ef62ce7 134 write(value);
emilmont 10:3bc89ef62ce7 135 return *this;
emilmont 10:3bc89ef62ce7 136 }
emilmont 10:3bc89ef62ce7 137
emilmont 10:3bc89ef62ce7 138 PwmOut& operator= (PwmOut& rhs) {
emilmont 10:3bc89ef62ce7 139 write(rhs.read());
emilmont 10:3bc89ef62ce7 140 return *this;
emilmont 10:3bc89ef62ce7 141 }
emilmont 10:3bc89ef62ce7 142
emilmont 10:3bc89ef62ce7 143 /** An operator shorthand for read()
emilmont 10:3bc89ef62ce7 144 */
emilmont 10:3bc89ef62ce7 145 operator float() {
emilmont 10:3bc89ef62ce7 146 return read();
emilmont 10:3bc89ef62ce7 147 }
emilmont 10:3bc89ef62ce7 148 #endif
emilmont 10:3bc89ef62ce7 149
emilmont 10:3bc89ef62ce7 150 protected:
emilmont 10:3bc89ef62ce7 151 pwmout_t _pwm;
emilmont 10:3bc89ef62ce7 152 };
emilmont 10:3bc89ef62ce7 153
emilmont 10:3bc89ef62ce7 154 } // namespace mbed
emilmont 10:3bc89ef62ce7 155
emilmont 10:3bc89ef62ce7 156 #endif
emilmont 10:3bc89ef62ce7 157
emilmont 10:3bc89ef62ce7 158 #endif