Bei Chen Liu / mbed-src

mbed library sources

Fork of mbed-src by mbed official

cpp/PwmOut.h@0:fd0d7bdfcdc2, 2012-11-20 (annotated)

Committer:
mbed_official
Date:
Tue Nov 20 17:24:08 2012 +0000
Revision:
0:fd0d7bdfcdc2
Child:
2:143cac498751
mbed sources

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mbed_official 0:fd0d7bdfcdc2 1 /* mbed Microcontroller Library
mbed_official 0:fd0d7bdfcdc2 2 * Copyright (c) 2006-2012 ARM Limited
mbed_official 0:fd0d7bdfcdc2 3 *
mbed_official 0:fd0d7bdfcdc2 4 * Permission is hereby granted, free of charge, to any person obtaining a copy
mbed_official 0:fd0d7bdfcdc2 5 * of this software and associated documentation files (the "Software"), to deal
mbed_official 0:fd0d7bdfcdc2 6 * in the Software without restriction, including without limitation the rights
mbed_official 0:fd0d7bdfcdc2 7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
mbed_official 0:fd0d7bdfcdc2 8 * copies of the Software, and to permit persons to whom the Software is
mbed_official 0:fd0d7bdfcdc2 9 * furnished to do so, subject to the following conditions:
mbed_official 0:fd0d7bdfcdc2 10 *
mbed_official 0:fd0d7bdfcdc2 11 * The above copyright notice and this permission notice shall be included in
mbed_official 0:fd0d7bdfcdc2 12 * all copies or substantial portions of the Software.
mbed_official 0:fd0d7bdfcdc2 13 *
mbed_official 0:fd0d7bdfcdc2 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
mbed_official 0:fd0d7bdfcdc2 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
mbed_official 0:fd0d7bdfcdc2 16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
mbed_official 0:fd0d7bdfcdc2 17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
mbed_official 0:fd0d7bdfcdc2 18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
mbed_official 0:fd0d7bdfcdc2 19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
mbed_official 0:fd0d7bdfcdc2 20 * SOFTWARE.
mbed_official 0:fd0d7bdfcdc2 21 */
mbed_official 0:fd0d7bdfcdc2 22 #ifndef MBED_PWMOUT_H
mbed_official 0:fd0d7bdfcdc2 23 #define MBED_PWMOUT_H
mbed_official 0:fd0d7bdfcdc2 24
mbed_official 0:fd0d7bdfcdc2 25 #include "platform.h"
mbed_official 0:fd0d7bdfcdc2 26
mbed_official 0:fd0d7bdfcdc2 27 #if DEVICE_PWMOUT
mbed_official 0:fd0d7bdfcdc2 28 #include "pwmout_api.h"
mbed_official 0:fd0d7bdfcdc2 29
mbed_official 0:fd0d7bdfcdc2 30 namespace mbed {
mbed_official 0:fd0d7bdfcdc2 31
mbed_official 0:fd0d7bdfcdc2 32 /** A pulse-width modulation digital output
mbed_official 0:fd0d7bdfcdc2 33 *
mbed_official 0:fd0d7bdfcdc2 34 * Example
mbed_official 0:fd0d7bdfcdc2 35 * @code
mbed_official 0:fd0d7bdfcdc2 36 * // Fade a led on.
mbed_official 0:fd0d7bdfcdc2 37 * #include "mbed.h"
mbed_official 0:fd0d7bdfcdc2 38 *
mbed_official 0:fd0d7bdfcdc2 39 * PwmOut led(LED1);
mbed_official 0:fd0d7bdfcdc2 40 *
mbed_official 0:fd0d7bdfcdc2 41 * int main() {
mbed_official 0:fd0d7bdfcdc2 42 * while(1) {
mbed_official 0:fd0d7bdfcdc2 43 * led = led + 0.01;
mbed_official 0:fd0d7bdfcdc2 44 * wait(0.2);
mbed_official 0:fd0d7bdfcdc2 45 * if(led == 1.0) {
mbed_official 0:fd0d7bdfcdc2 46 * led = 0;
mbed_official 0:fd0d7bdfcdc2 47 * }
mbed_official 0:fd0d7bdfcdc2 48 * }
mbed_official 0:fd0d7bdfcdc2 49 * }
mbed_official 0:fd0d7bdfcdc2 50 * @endcode
mbed_official 0:fd0d7bdfcdc2 51 *
mbed_official 0:fd0d7bdfcdc2 52 * @note
mbed_official 0:fd0d7bdfcdc2 53 * On the LPC1768 and LPC2368, the PWMs all share the same
mbed_official 0:fd0d7bdfcdc2 54 * period - if you change the period for one, you change it for all.
mbed_official 0:fd0d7bdfcdc2 55 * Although routines that change the period maintain the duty cycle
mbed_official 0:fd0d7bdfcdc2 56 * for its PWM, all other PWMs will require their duty cycle to be
mbed_official 0:fd0d7bdfcdc2 57 * refreshed.
mbed_official 0:fd0d7bdfcdc2 58 */
mbed_official 0:fd0d7bdfcdc2 59 class PwmOut {
mbed_official 0:fd0d7bdfcdc2 60
mbed_official 0:fd0d7bdfcdc2 61 public:
mbed_official 0:fd0d7bdfcdc2 62
mbed_official 0:fd0d7bdfcdc2 63 /** Create a PwmOut connected to the specified pin
mbed_official 0:fd0d7bdfcdc2 64 *
mbed_official 0:fd0d7bdfcdc2 65 * @param pin PwmOut pin to connect to
mbed_official 0:fd0d7bdfcdc2 66 */
mbed_official 0:fd0d7bdfcdc2 67 PwmOut(PinName pin) {
mbed_official 0:fd0d7bdfcdc2 68 pwmout_init(&_pwm, pin);
mbed_official 0:fd0d7bdfcdc2 69 }
mbed_official 0:fd0d7bdfcdc2 70
mbed_official 0:fd0d7bdfcdc2 71 /** Set the ouput duty-cycle, specified as a percentage (float)
mbed_official 0:fd0d7bdfcdc2 72 *
mbed_official 0:fd0d7bdfcdc2 73 * @param value A floating-point value representing the output duty-cycle,
mbed_official 0:fd0d7bdfcdc2 74 * specified as a percentage. The value should lie between
mbed_official 0:fd0d7bdfcdc2 75 * 0.0f (representing on 0%) and 1.0f (representing on 100%).
mbed_official 0:fd0d7bdfcdc2 76 * Values outside this range will be saturated to 0.0f or 1.0f.
mbed_official 0:fd0d7bdfcdc2 77 */
mbed_official 0:fd0d7bdfcdc2 78 void write(float value) {
mbed_official 0:fd0d7bdfcdc2 79 pwmout_write(&_pwm, value);
mbed_official 0:fd0d7bdfcdc2 80 }
mbed_official 0:fd0d7bdfcdc2 81
mbed_official 0:fd0d7bdfcdc2 82 /** Return the current output duty-cycle setting, measured as a percentage (float)
mbed_official 0:fd0d7bdfcdc2 83 *
mbed_official 0:fd0d7bdfcdc2 84 * @returns
mbed_official 0:fd0d7bdfcdc2 85 * A floating-point value representing the current duty-cycle being output on the pin,
mbed_official 0:fd0d7bdfcdc2 86 * measured as a percentage. The returned value will lie between
mbed_official 0:fd0d7bdfcdc2 87 * 0.0f (representing on 0%) and 1.0f (representing on 100%).
mbed_official 0:fd0d7bdfcdc2 88 *
mbed_official 0:fd0d7bdfcdc2 89 * @note
mbed_official 0:fd0d7bdfcdc2 90 * This value may not match exactly the value set by a previous <write>.
mbed_official 0:fd0d7bdfcdc2 91 */
mbed_official 0:fd0d7bdfcdc2 92 float read() {
mbed_official 0:fd0d7bdfcdc2 93 return pwmout_read(&_pwm);
mbed_official 0:fd0d7bdfcdc2 94 }
mbed_official 0:fd0d7bdfcdc2 95
mbed_official 0:fd0d7bdfcdc2 96 /** Set the PWM period, specified in seconds (float), keeping the duty cycle the same.
mbed_official 0:fd0d7bdfcdc2 97 *
mbed_official 0:fd0d7bdfcdc2 98 * @note
mbed_official 0:fd0d7bdfcdc2 99 * The resolution is currently in microseconds; periods smaller than this
mbed_official 0:fd0d7bdfcdc2 100 * will be set to zero.
mbed_official 0:fd0d7bdfcdc2 101 */
mbed_official 0:fd0d7bdfcdc2 102 void period(float seconds) {
mbed_official 0:fd0d7bdfcdc2 103 pwmout_period(&_pwm, seconds);
mbed_official 0:fd0d7bdfcdc2 104 }
mbed_official 0:fd0d7bdfcdc2 105
mbed_official 0:fd0d7bdfcdc2 106 /** Set the PWM period, specified in milli-seconds (int), keeping the duty cycle the same.
mbed_official 0:fd0d7bdfcdc2 107 */
mbed_official 0:fd0d7bdfcdc2 108 void period_ms(int ms) {
mbed_official 0:fd0d7bdfcdc2 109 pwmout_period_ms(&_pwm, ms);
mbed_official 0:fd0d7bdfcdc2 110 }
mbed_official 0:fd0d7bdfcdc2 111
mbed_official 0:fd0d7bdfcdc2 112 /** Set the PWM period, specified in micro-seconds (int), keeping the duty cycle the same.
mbed_official 0:fd0d7bdfcdc2 113 */
mbed_official 0:fd0d7bdfcdc2 114 void period_us(int us) {
mbed_official 0:fd0d7bdfcdc2 115 pwmout_period_us(&_pwm, us);
mbed_official 0:fd0d7bdfcdc2 116 }
mbed_official 0:fd0d7bdfcdc2 117
mbed_official 0:fd0d7bdfcdc2 118 /** Set the PWM pulsewidth, specified in seconds (float), keeping the period the same.
mbed_official 0:fd0d7bdfcdc2 119 */
mbed_official 0:fd0d7bdfcdc2 120 void pulsewidth(float seconds) {
mbed_official 0:fd0d7bdfcdc2 121 pwmout_pulsewidth(&_pwm, seconds);
mbed_official 0:fd0d7bdfcdc2 122 }
mbed_official 0:fd0d7bdfcdc2 123
mbed_official 0:fd0d7bdfcdc2 124 /** Set the PWM pulsewidth, specified in milli-seconds (int), keeping the period the same.
mbed_official 0:fd0d7bdfcdc2 125 */
mbed_official 0:fd0d7bdfcdc2 126 void pulsewidth_ms(int ms) {
mbed_official 0:fd0d7bdfcdc2 127 pwmout_pulsewidth_ms(&_pwm, ms);
mbed_official 0:fd0d7bdfcdc2 128 }
mbed_official 0:fd0d7bdfcdc2 129
mbed_official 0:fd0d7bdfcdc2 130 /** Set the PWM pulsewidth, specified in micro-seconds (int), keeping the period the same.
mbed_official 0:fd0d7bdfcdc2 131 */
mbed_official 0:fd0d7bdfcdc2 132 void pulsewidth_us(int us) {
mbed_official 0:fd0d7bdfcdc2 133 pwmout_pulsewidth_us(&_pwm, us);
mbed_official 0:fd0d7bdfcdc2 134 }
mbed_official 0:fd0d7bdfcdc2 135
mbed_official 0:fd0d7bdfcdc2 136 #ifdef MBED_OPERATORS
mbed_official 0:fd0d7bdfcdc2 137 /** A operator shorthand for write()
mbed_official 0:fd0d7bdfcdc2 138 */
mbed_official 0:fd0d7bdfcdc2 139 PwmOut& operator= (float value) {
mbed_official 0:fd0d7bdfcdc2 140 write(value);
mbed_official 0:fd0d7bdfcdc2 141 return *this;
mbed_official 0:fd0d7bdfcdc2 142 }
mbed_official 0:fd0d7bdfcdc2 143
mbed_official 0:fd0d7bdfcdc2 144 PwmOut& operator= (PwmOut& rhs) {
mbed_official 0:fd0d7bdfcdc2 145 write(rhs.read());
mbed_official 0:fd0d7bdfcdc2 146 return *this;
mbed_official 0:fd0d7bdfcdc2 147 }
mbed_official 0:fd0d7bdfcdc2 148
mbed_official 0:fd0d7bdfcdc2 149 /** An operator shorthand for read()
mbed_official 0:fd0d7bdfcdc2 150 */
mbed_official 0:fd0d7bdfcdc2 151 operator float() {
mbed_official 0:fd0d7bdfcdc2 152 return read();
mbed_official 0:fd0d7bdfcdc2 153 }
mbed_official 0:fd0d7bdfcdc2 154 #endif
mbed_official 0:fd0d7bdfcdc2 155
mbed_official 0:fd0d7bdfcdc2 156 protected:
mbed_official 0:fd0d7bdfcdc2 157 pwmout_t _pwm;
mbed_official 0:fd0d7bdfcdc2 158 };
mbed_official 0:fd0d7bdfcdc2 159
mbed_official 0:fd0d7bdfcdc2 160 } // namespace mbed
mbed_official 0:fd0d7bdfcdc2 161
mbed_official 0:fd0d7bdfcdc2 162 #endif
mbed_official 0:fd0d7bdfcdc2 163
mbed_official 0:fd0d7bdfcdc2 164 #endif