Yihui Xiong / mbed-src-nrf51822

customized mbed library sources for nrf51822

Dependents:   Grove_Node Potentiometer BLE_Beacon I2C_Scanner

api/PwmOut.h@0:700cadd8b708, 2014-11-04 (annotated)

Committer:
yihui
Date:
Tue Nov 04 07:38:53 2014 +0000
Revision:
0:700cadd8b708
customized mbed-src library for nrf51822

Who changed what in which revision?

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yihui 0:700cadd8b708 1 /* mbed Microcontroller Library
yihui 0:700cadd8b708 2 * Copyright (c) 2006-2013 ARM Limited
yihui 0:700cadd8b708 3 *
yihui 0:700cadd8b708 4 * Licensed under the Apache License, Version 2.0 (the "License");
yihui 0:700cadd8b708 5 * you may not use this file except in compliance with the License.
yihui 0:700cadd8b708 6 * You may obtain a copy of the License at
yihui 0:700cadd8b708 7 *
yihui 0:700cadd8b708 8 * http://www.apache.org/licenses/LICENSE-2.0
yihui 0:700cadd8b708 9 *
yihui 0:700cadd8b708 10 * Unless required by applicable law or agreed to in writing, software
yihui 0:700cadd8b708 11 * distributed under the License is distributed on an "AS IS" BASIS,
yihui 0:700cadd8b708 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
yihui 0:700cadd8b708 13 * See the License for the specific language governing permissions and
yihui 0:700cadd8b708 14 * limitations under the License.
yihui 0:700cadd8b708 15 */
yihui 0:700cadd8b708 16 #ifndef MBED_PWMOUT_H
yihui 0:700cadd8b708 17 #define MBED_PWMOUT_H
yihui 0:700cadd8b708 18
yihui 0:700cadd8b708 19 #include "platform.h"
yihui 0:700cadd8b708 20
yihui 0:700cadd8b708 21 #if DEVICE_PWMOUT
yihui 0:700cadd8b708 22 #include "pwmout_api.h"
yihui 0:700cadd8b708 23
yihui 0:700cadd8b708 24 namespace mbed {
yihui 0:700cadd8b708 25
yihui 0:700cadd8b708 26 /** A pulse-width modulation digital output
yihui 0:700cadd8b708 27 *
yihui 0:700cadd8b708 28 * Example
yihui 0:700cadd8b708 29 * @code
yihui 0:700cadd8b708 30 * // Fade a led on.
yihui 0:700cadd8b708 31 * #include "mbed.h"
yihui 0:700cadd8b708 32 *
yihui 0:700cadd8b708 33 * PwmOut led(LED1);
yihui 0:700cadd8b708 34 *
yihui 0:700cadd8b708 35 * int main() {
yihui 0:700cadd8b708 36 * while(1) {
yihui 0:700cadd8b708 37 * led = led + 0.01;
yihui 0:700cadd8b708 38 * wait(0.2);
yihui 0:700cadd8b708 39 * if(led == 1.0) {
yihui 0:700cadd8b708 40 * led = 0;
yihui 0:700cadd8b708 41 * }
yihui 0:700cadd8b708 42 * }
yihui 0:700cadd8b708 43 * }
yihui 0:700cadd8b708 44 * @endcode
yihui 0:700cadd8b708 45 *
yihui 0:700cadd8b708 46 * @note
yihui 0:700cadd8b708 47 * On the LPC1768 and LPC2368, the PWMs all share the same
yihui 0:700cadd8b708 48 * period - if you change the period for one, you change it for all.
yihui 0:700cadd8b708 49 * Although routines that change the period maintain the duty cycle
yihui 0:700cadd8b708 50 * for its PWM, all other PWMs will require their duty cycle to be
yihui 0:700cadd8b708 51 * refreshed.
yihui 0:700cadd8b708 52 */
yihui 0:700cadd8b708 53 class PwmOut {
yihui 0:700cadd8b708 54
yihui 0:700cadd8b708 55 public:
yihui 0:700cadd8b708 56
yihui 0:700cadd8b708 57 /** Create a PwmOut connected to the specified pin
yihui 0:700cadd8b708 58 *
yihui 0:700cadd8b708 59 * @param pin PwmOut pin to connect to
yihui 0:700cadd8b708 60 */
yihui 0:700cadd8b708 61 PwmOut(PinName pin) {
yihui 0:700cadd8b708 62 pwmout_init(&_pwm, pin);
yihui 0:700cadd8b708 63 }
yihui 0:700cadd8b708 64
yihui 0:700cadd8b708 65 ~PwmOut() {
yihui 0:700cadd8b708 66 pwmout_free(&_pwm);
yihui 0:700cadd8b708 67 }
yihui 0:700cadd8b708 68
yihui 0:700cadd8b708 69 /** Set the ouput duty-cycle, specified as a percentage (float)
yihui 0:700cadd8b708 70 *
yihui 0:700cadd8b708 71 * @param value A floating-point value representing the output duty-cycle,
yihui 0:700cadd8b708 72 * specified as a percentage. The value should lie between
yihui 0:700cadd8b708 73 * 0.0f (representing on 0%) and 1.0f (representing on 100%).
yihui 0:700cadd8b708 74 * Values outside this range will be saturated to 0.0f or 1.0f.
yihui 0:700cadd8b708 75 */
yihui 0:700cadd8b708 76 void write(float value) {
yihui 0:700cadd8b708 77 pwmout_write(&_pwm, value);
yihui 0:700cadd8b708 78 }
yihui 0:700cadd8b708 79
yihui 0:700cadd8b708 80 /** Return the current output duty-cycle setting, measured as a percentage (float)
yihui 0:700cadd8b708 81 *
yihui 0:700cadd8b708 82 * @returns
yihui 0:700cadd8b708 83 * A floating-point value representing the current duty-cycle being output on the pin,
yihui 0:700cadd8b708 84 * measured as a percentage. The returned value will lie between
yihui 0:700cadd8b708 85 * 0.0f (representing on 0%) and 1.0f (representing on 100%).
yihui 0:700cadd8b708 86 *
yihui 0:700cadd8b708 87 * @note
yihui 0:700cadd8b708 88 * This value may not match exactly the value set by a previous <write>.
yihui 0:700cadd8b708 89 */
yihui 0:700cadd8b708 90 float read() {
yihui 0:700cadd8b708 91 return pwmout_read(&_pwm);
yihui 0:700cadd8b708 92 }
yihui 0:700cadd8b708 93
yihui 0:700cadd8b708 94 /** Set the PWM period, specified in seconds (float), keeping the duty cycle the same.
yihui 0:700cadd8b708 95 *
yihui 0:700cadd8b708 96 * @note
yihui 0:700cadd8b708 97 * The resolution is currently in microseconds; periods smaller than this
yihui 0:700cadd8b708 98 * will be set to zero.
yihui 0:700cadd8b708 99 */
yihui 0:700cadd8b708 100 void period(float seconds) {
yihui 0:700cadd8b708 101 pwmout_period(&_pwm, seconds);
yihui 0:700cadd8b708 102 }
yihui 0:700cadd8b708 103
yihui 0:700cadd8b708 104 /** Set the PWM period, specified in milli-seconds (int), keeping the duty cycle the same.
yihui 0:700cadd8b708 105 */
yihui 0:700cadd8b708 106 void period_ms(int ms) {
yihui 0:700cadd8b708 107 pwmout_period_ms(&_pwm, ms);
yihui 0:700cadd8b708 108 }
yihui 0:700cadd8b708 109
yihui 0:700cadd8b708 110 /** Set the PWM period, specified in micro-seconds (int), keeping the duty cycle the same.
yihui 0:700cadd8b708 111 */
yihui 0:700cadd8b708 112 void period_us(int us) {
yihui 0:700cadd8b708 113 pwmout_period_us(&_pwm, us);
yihui 0:700cadd8b708 114 }
yihui 0:700cadd8b708 115
yihui 0:700cadd8b708 116 /** Set the PWM pulsewidth, specified in seconds (float), keeping the period the same.
yihui 0:700cadd8b708 117 */
yihui 0:700cadd8b708 118 void pulsewidth(float seconds) {
yihui 0:700cadd8b708 119 pwmout_pulsewidth(&_pwm, seconds);
yihui 0:700cadd8b708 120 }
yihui 0:700cadd8b708 121
yihui 0:700cadd8b708 122 /** Set the PWM pulsewidth, specified in milli-seconds (int), keeping the period the same.
yihui 0:700cadd8b708 123 */
yihui 0:700cadd8b708 124 void pulsewidth_ms(int ms) {
yihui 0:700cadd8b708 125 pwmout_pulsewidth_ms(&_pwm, ms);
yihui 0:700cadd8b708 126 }
yihui 0:700cadd8b708 127
yihui 0:700cadd8b708 128 /** Set the PWM pulsewidth, specified in micro-seconds (int), keeping the period the same.
yihui 0:700cadd8b708 129 */
yihui 0:700cadd8b708 130 void pulsewidth_us(int us) {
yihui 0:700cadd8b708 131 pwmout_pulsewidth_us(&_pwm, us);
yihui 0:700cadd8b708 132 }
yihui 0:700cadd8b708 133
yihui 0:700cadd8b708 134 #ifdef MBED_OPERATORS
yihui 0:700cadd8b708 135 /** A operator shorthand for write()
yihui 0:700cadd8b708 136 */
yihui 0:700cadd8b708 137 PwmOut& operator= (float value) {
yihui 0:700cadd8b708 138 write(value);
yihui 0:700cadd8b708 139 return *this;
yihui 0:700cadd8b708 140 }
yihui 0:700cadd8b708 141
yihui 0:700cadd8b708 142 PwmOut& operator= (PwmOut& rhs) {
yihui 0:700cadd8b708 143 write(rhs.read());
yihui 0:700cadd8b708 144 return *this;
yihui 0:700cadd8b708 145 }
yihui 0:700cadd8b708 146
yihui 0:700cadd8b708 147 /** An operator shorthand for read()
yihui 0:700cadd8b708 148 */
yihui 0:700cadd8b708 149 operator float() {
yihui 0:700cadd8b708 150 return read();
yihui 0:700cadd8b708 151 }
yihui 0:700cadd8b708 152 #endif
yihui 0:700cadd8b708 153
yihui 0:700cadd8b708 154 protected:
yihui 0:700cadd8b708 155 pwmout_t _pwm;
yihui 0:700cadd8b708 156 };
yihui 0:700cadd8b708 157
yihui 0:700cadd8b708 158 } // namespace mbed
yihui 0:700cadd8b708 159
yihui 0:700cadd8b708 160 #endif
yihui 0:700cadd8b708 161
yihui 0:700cadd8b708 162 #endif