Jhon Plantikow / Dataloger

Dataloger

PwmOut.h@0:666850d06c9f, 2015-08-20 (annotated)

Committer:
jhon309
Date:
Thu Aug 20 00:37:14 2015 +0000
Revision:
0:666850d06c9f
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jhon309 0:666850d06c9f 1 /* mbed Microcontroller Library
jhon309 0:666850d06c9f 2 * Copyright (c) 2006-2013 ARM Limited
jhon309 0:666850d06c9f 3 *
jhon309 0:666850d06c9f 4 * Licensed under the Apache License, Version 2.0 (the "License");
jhon309 0:666850d06c9f 5 * you may not use this file except in compliance with the License.
jhon309 0:666850d06c9f 6 * You may obtain a copy of the License at
jhon309 0:666850d06c9f 7 *
jhon309 0:666850d06c9f 8 * http://www.apache.org/licenses/LICENSE-2.0
jhon309 0:666850d06c9f 9 *
jhon309 0:666850d06c9f 10 * Unless required by applicable law or agreed to in writing, software
jhon309 0:666850d06c9f 11 * distributed under the License is distributed on an "AS IS" BASIS,
jhon309 0:666850d06c9f 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
jhon309 0:666850d06c9f 13 * See the License for the specific language governing permissions and
jhon309 0:666850d06c9f 14 * limitations under the License.
jhon309 0:666850d06c9f 15 */
jhon309 0:666850d06c9f 16 #ifndef MBED_PWMOUT_H
jhon309 0:666850d06c9f 17 #define MBED_PWMOUT_H
jhon309 0:666850d06c9f 18
jhon309 0:666850d06c9f 19 #include "platform.h"
jhon309 0:666850d06c9f 20
jhon309 0:666850d06c9f 21 #if DEVICE_PWMOUT
jhon309 0:666850d06c9f 22 #include "pwmout_api.h"
jhon309 0:666850d06c9f 23
jhon309 0:666850d06c9f 24 namespace mbed {
jhon309 0:666850d06c9f 25
jhon309 0:666850d06c9f 26 /** A pulse-width modulation digital output
jhon309 0:666850d06c9f 27 *
jhon309 0:666850d06c9f 28 * Example
jhon309 0:666850d06c9f 29 * @code
jhon309 0:666850d06c9f 30 * // Fade a led on.
jhon309 0:666850d06c9f 31 * #include "mbed.h"
jhon309 0:666850d06c9f 32 *
jhon309 0:666850d06c9f 33 * PwmOut led(LED1);
jhon309 0:666850d06c9f 34 *
jhon309 0:666850d06c9f 35 * int main() {
jhon309 0:666850d06c9f 36 * while(1) {
jhon309 0:666850d06c9f 37 * led = led + 0.01;
jhon309 0:666850d06c9f 38 * wait(0.2);
jhon309 0:666850d06c9f 39 * if(led == 1.0) {
jhon309 0:666850d06c9f 40 * led = 0;
jhon309 0:666850d06c9f 41 * }
jhon309 0:666850d06c9f 42 * }
jhon309 0:666850d06c9f 43 * }
jhon309 0:666850d06c9f 44 * @endcode
jhon309 0:666850d06c9f 45 *
jhon309 0:666850d06c9f 46 * @note
jhon309 0:666850d06c9f 47 * On the LPC1768 and LPC2368, the PWMs all share the same
jhon309 0:666850d06c9f 48 * period - if you change the period for one, you change it for all.
jhon309 0:666850d06c9f 49 * Although routines that change the period maintain the duty cycle
jhon309 0:666850d06c9f 50 * for its PWM, all other PWMs will require their duty cycle to be
jhon309 0:666850d06c9f 51 * refreshed.
jhon309 0:666850d06c9f 52 */
jhon309 0:666850d06c9f 53 class PwmOut {
jhon309 0:666850d06c9f 54
jhon309 0:666850d06c9f 55 public:
jhon309 0:666850d06c9f 56
jhon309 0:666850d06c9f 57 /** Create a PwmOut connected to the specified pin
jhon309 0:666850d06c9f 58 *
jhon309 0:666850d06c9f 59 * @param pin PwmOut pin to connect to
jhon309 0:666850d06c9f 60 */
jhon309 0:666850d06c9f 61 PwmOut(PinName pin) {
jhon309 0:666850d06c9f 62 pwmout_init(&_pwm, pin);
jhon309 0:666850d06c9f 63 }
jhon309 0:666850d06c9f 64
jhon309 0:666850d06c9f 65 /** Set the ouput duty-cycle, specified as a percentage (float)
jhon309 0:666850d06c9f 66 *
jhon309 0:666850d06c9f 67 * @param value A floating-point value representing the output duty-cycle,
jhon309 0:666850d06c9f 68 * specified as a percentage. The value should lie between
jhon309 0:666850d06c9f 69 * 0.0f (representing on 0%) and 1.0f (representing on 100%).
jhon309 0:666850d06c9f 70 * Values outside this range will be saturated to 0.0f or 1.0f.
jhon309 0:666850d06c9f 71 */
jhon309 0:666850d06c9f 72 void write(float value) {
jhon309 0:666850d06c9f 73 pwmout_write(&_pwm, value);
jhon309 0:666850d06c9f 74 }
jhon309 0:666850d06c9f 75
jhon309 0:666850d06c9f 76 /** Return the current output duty-cycle setting, measured as a percentage (float)
jhon309 0:666850d06c9f 77 *
jhon309 0:666850d06c9f 78 * @returns
jhon309 0:666850d06c9f 79 * A floating-point value representing the current duty-cycle being output on the pin,
jhon309 0:666850d06c9f 80 * measured as a percentage. The returned value will lie between
jhon309 0:666850d06c9f 81 * 0.0f (representing on 0%) and 1.0f (representing on 100%).
jhon309 0:666850d06c9f 82 *
jhon309 0:666850d06c9f 83 * @note
jhon309 0:666850d06c9f 84 * This value may not match exactly the value set by a previous <write>.
jhon309 0:666850d06c9f 85 */
jhon309 0:666850d06c9f 86 float read() {
jhon309 0:666850d06c9f 87 return pwmout_read(&_pwm);
jhon309 0:666850d06c9f 88 }
jhon309 0:666850d06c9f 89
jhon309 0:666850d06c9f 90 /** Set the PWM period, specified in seconds (float), keeping the duty cycle the same.
jhon309 0:666850d06c9f 91 *
jhon309 0:666850d06c9f 92 * @note
jhon309 0:666850d06c9f 93 * The resolution is currently in microseconds; periods smaller than this
jhon309 0:666850d06c9f 94 * will be set to zero.
jhon309 0:666850d06c9f 95 */
jhon309 0:666850d06c9f 96 void period(float seconds) {
jhon309 0:666850d06c9f 97 pwmout_period(&_pwm, seconds);
jhon309 0:666850d06c9f 98 }
jhon309 0:666850d06c9f 99
jhon309 0:666850d06c9f 100 /** Set the PWM period, specified in milli-seconds (int), keeping the duty cycle the same.
jhon309 0:666850d06c9f 101 */
jhon309 0:666850d06c9f 102 void period_ms(int ms) {
jhon309 0:666850d06c9f 103 pwmout_period_ms(&_pwm, ms);
jhon309 0:666850d06c9f 104 }
jhon309 0:666850d06c9f 105
jhon309 0:666850d06c9f 106 /** Set the PWM period, specified in micro-seconds (int), keeping the duty cycle the same.
jhon309 0:666850d06c9f 107 */
jhon309 0:666850d06c9f 108 void period_us(int us) {
jhon309 0:666850d06c9f 109 pwmout_period_us(&_pwm, us);
jhon309 0:666850d06c9f 110 }
jhon309 0:666850d06c9f 111
jhon309 0:666850d06c9f 112 /** Set the PWM pulsewidth, specified in seconds (float), keeping the period the same.
jhon309 0:666850d06c9f 113 */
jhon309 0:666850d06c9f 114 void pulsewidth(float seconds) {
jhon309 0:666850d06c9f 115 pwmout_pulsewidth(&_pwm, seconds);
jhon309 0:666850d06c9f 116 }
jhon309 0:666850d06c9f 117
jhon309 0:666850d06c9f 118 /** Set the PWM pulsewidth, specified in milli-seconds (int), keeping the period the same.
jhon309 0:666850d06c9f 119 */
jhon309 0:666850d06c9f 120 void pulsewidth_ms(int ms) {
jhon309 0:666850d06c9f 121 pwmout_pulsewidth_ms(&_pwm, ms);
jhon309 0:666850d06c9f 122 }
jhon309 0:666850d06c9f 123
jhon309 0:666850d06c9f 124 /** Set the PWM pulsewidth, specified in micro-seconds (int), keeping the period the same.
jhon309 0:666850d06c9f 125 */
jhon309 0:666850d06c9f 126 void pulsewidth_us(int us) {
jhon309 0:666850d06c9f 127 pwmout_pulsewidth_us(&_pwm, us);
jhon309 0:666850d06c9f 128 }
jhon309 0:666850d06c9f 129
jhon309 0:666850d06c9f 130 #ifdef MBED_OPERATORS
jhon309 0:666850d06c9f 131 /** A operator shorthand for write()
jhon309 0:666850d06c9f 132 */
jhon309 0:666850d06c9f 133 PwmOut& operator= (float value) {
jhon309 0:666850d06c9f 134 write(value);
jhon309 0:666850d06c9f 135 return *this;
jhon309 0:666850d06c9f 136 }
jhon309 0:666850d06c9f 137
jhon309 0:666850d06c9f 138 PwmOut& operator= (PwmOut& rhs) {
jhon309 0:666850d06c9f 139 write(rhs.read());
jhon309 0:666850d06c9f 140 return *this;
jhon309 0:666850d06c9f 141 }
jhon309 0:666850d06c9f 142
jhon309 0:666850d06c9f 143 /** An operator shorthand for read()
jhon309 0:666850d06c9f 144 */
jhon309 0:666850d06c9f 145 operator float() {
jhon309 0:666850d06c9f 146 return read();
jhon309 0:666850d06c9f 147 }
jhon309 0:666850d06c9f 148 #endif
jhon309 0:666850d06c9f 149
jhon309 0:666850d06c9f 150 protected:
jhon309 0:666850d06c9f 151 pwmout_t _pwm;
jhon309 0:666850d06c9f 152 };
jhon309 0:666850d06c9f 153
jhon309 0:666850d06c9f 154 } // namespace mbed
jhon309 0:666850d06c9f 155
jhon309 0:666850d06c9f 156 #endif
jhon309 0:666850d06c9f 157
jhon309 0:666850d06c9f 158 #endif