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PwmOut.h@64:75c1708b266b, 2013-07-05 (annotated)

Committer:
ldyz
Date:
Fri Jul 05 13:16:13 2013 +0000
Revision:
64:75c1708b266b
Parent:
59:0883845fe643 
test

Who changed what in which revision?

UserRevisionLine numberNew contents of line
emilmont 44:24d45a770a51 1 /* mbed Microcontroller Library
emilmont 54:71b101360fb9 2 * Copyright (c) 2006-2013 ARM Limited
emilmont 44:24d45a770a51 3 *
emilmont 59:0883845fe643 4 * Licensed under the Apache License, Version 2.0 (the "License");
emilmont 59:0883845fe643 5 * you may not use this file except in compliance with the License.
emilmont 59:0883845fe643 6 * You may obtain a copy of the License at
emilmont 59:0883845fe643 7 *
emilmont 59:0883845fe643 8 * http://www.apache.org/licenses/LICENSE-2.0
emilmont 44:24d45a770a51 9 *
emilmont 59:0883845fe643 10 * Unless required by applicable law or agreed to in writing, software
emilmont 59:0883845fe643 11 * distributed under the License is distributed on an "AS IS" BASIS,
emilmont 59:0883845fe643 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
emilmont 59:0883845fe643 13 * See the License for the specific language governing permissions and
emilmont 59:0883845fe643 14 * limitations under the License.
emilmont 44:24d45a770a51 15 */
simon.ford@mbed.co.uk 0:82220227f4fa 16 #ifndef MBED_PWMOUT_H
simon.ford@mbed.co.uk 0:82220227f4fa 17 #define MBED_PWMOUT_H
simon.ford@mbed.co.uk 0:82220227f4fa 18
emilmont 44:24d45a770a51 19 #include "platform.h"
emilmont 27:7110ebee3484 20
emilmont 27:7110ebee3484 21 #if DEVICE_PWMOUT
emilmont 44:24d45a770a51 22 #include "pwmout_api.h"
simon.ford@mbed.co.uk 0:82220227f4fa 23
simon.ford@mbed.co.uk 0:82220227f4fa 24 namespace mbed {
simon.ford@mbed.co.uk 0:82220227f4fa 25
emilmont 43:e2ed12d17f06 26 /** A pulse-width modulation digital output
simon.ford@mbed.co.uk 5:62573be585e9 27 *
rolf.meyer@arm.com 11:1c1ebd0324fa 28 * Example
emilmont 43:e2ed12d17f06 29 * @code
emilmont 43:e2ed12d17f06 30 * // Fade a led on.
emilmont 43:e2ed12d17f06 31 * #include "mbed.h"
simon.ford@mbed.co.uk 18:b3c9f16cbb96 32 *
emilmont 43:e2ed12d17f06 33 * PwmOut led(LED1);
emilmont 55:d722ed6a4237 34 *
emilmont 43:e2ed12d17f06 35 * int main() {
emilmont 43:e2ed12d17f06 36 * while(1) {
emilmont 43:e2ed12d17f06 37 * led = led + 0.01;
emilmont 43:e2ed12d17f06 38 * wait(0.2);
emilmont 43:e2ed12d17f06 39 * if(led == 1.0) {
emilmont 43:e2ed12d17f06 40 * led = 0;
emilmont 43:e2ed12d17f06 41 * }
emilmont 43:e2ed12d17f06 42 * }
emilmont 43:e2ed12d17f06 43 * }
emilmont 43:e2ed12d17f06 44 * @endcode
emilmont 43:e2ed12d17f06 45 *
emilmont 43:e2ed12d17f06 46 * @note
emilmont 43:e2ed12d17f06 47 * On the LPC1768 and LPC2368, the PWMs all share the same
simon.ford@mbed.co.uk 18:b3c9f16cbb96 48 * period - if you change the period for one, you change it for all.
simon.ford@mbed.co.uk 18:b3c9f16cbb96 49 * Although routines that change the period maintain the duty cycle
simon.ford@mbed.co.uk 18:b3c9f16cbb96 50 * for its PWM, all other PWMs will require their duty cycle to be
simon.ford@mbed.co.uk 18:b3c9f16cbb96 51 * refreshed.
simon.ford@mbed.co.uk 0:82220227f4fa 52 */
emilmont 44:24d45a770a51 53 class PwmOut {
simon.ford@mbed.co.uk 0:82220227f4fa 54
simon.ford@mbed.co.uk 0:82220227f4fa 55 public:
simon.ford@mbed.co.uk 0:82220227f4fa 56
emilmont 43:e2ed12d17f06 57 /** Create a PwmOut connected to the specified pin
rolf.meyer@arm.com 11:1c1ebd0324fa 58 *
emilmont 43:e2ed12d17f06 59 * @param pin PwmOut pin to connect to
rolf.meyer@arm.com 11:1c1ebd0324fa 60 */
emilmont 44:24d45a770a51 61 PwmOut(PinName pin) {
emilmont 44:24d45a770a51 62 pwmout_init(&_pwm, pin);
emilmont 44:24d45a770a51 63 }
simon.ford@mbed.co.uk 0:82220227f4fa 64
emilmont 43:e2ed12d17f06 65 /** Set the ouput duty-cycle, specified as a percentage (float)
rolf.meyer@arm.com 11:1c1ebd0324fa 66 *
emilmont 55:d722ed6a4237 67 * @param value A floating-point value representing the output duty-cycle,
rolf.meyer@arm.com 11:1c1ebd0324fa 68 * specified as a percentage. The value should lie between
rolf.meyer@arm.com 11:1c1ebd0324fa 69 * 0.0f (representing on 0%) and 1.0f (representing on 100%).
emilmont 44:24d45a770a51 70 * Values outside this range will be saturated to 0.0f or 1.0f.
rolf.meyer@arm.com 11:1c1ebd0324fa 71 */
emilmont 44:24d45a770a51 72 void write(float value) {
emilmont 44:24d45a770a51 73 pwmout_write(&_pwm, value);
emilmont 44:24d45a770a51 74 }
simon.ford@mbed.co.uk 0:82220227f4fa 75
emilmont 43:e2ed12d17f06 76 /** Return the current output duty-cycle setting, measured as a percentage (float)
simon.ford@mbed.co.uk 0:82220227f4fa 77 *
emilmont 43:e2ed12d17f06 78 * @returns
emilmont 55:d722ed6a4237 79 * A floating-point value representing the current duty-cycle being output on the pin,
rolf.meyer@arm.com 11:1c1ebd0324fa 80 * measured as a percentage. The returned value will lie between
rolf.meyer@arm.com 11:1c1ebd0324fa 81 * 0.0f (representing on 0%) and 1.0f (representing on 100%).
rolf.meyer@arm.com 11:1c1ebd0324fa 82 *
emilmont 43:e2ed12d17f06 83 * @note
emilmont 44:24d45a770a51 84 * This value may not match exactly the value set by a previous <write>.
rolf.meyer@arm.com 11:1c1ebd0324fa 85 */
emilmont 44:24d45a770a51 86 float read() {
emilmont 44:24d45a770a51 87 return pwmout_read(&_pwm);
emilmont 44:24d45a770a51 88 }
emilmont 55:d722ed6a4237 89
emilmont 43:e2ed12d17f06 90 /** Set the PWM period, specified in seconds (float), keeping the duty cycle the same.
simon.ford@mbed.co.uk 18:b3c9f16cbb96 91 *
emilmont 43:e2ed12d17f06 92 * @note
emilmont 44:24d45a770a51 93 * The resolution is currently in microseconds; periods smaller than this
emilmont 44:24d45a770a51 94 * will be set to zero.
rolf.meyer@arm.com 11:1c1ebd0324fa 95 */
emilmont 44:24d45a770a51 96 void period(float seconds) {
emilmont 44:24d45a770a51 97 pwmout_period(&_pwm, seconds);
emilmont 44:24d45a770a51 98 }
simon.ford@mbed.co.uk 0:82220227f4fa 99
emilmont 43:e2ed12d17f06 100 /** Set the PWM period, specified in milli-seconds (int), keeping the duty cycle the same.
rolf.meyer@arm.com 11:1c1ebd0324fa 101 */
emilmont 44:24d45a770a51 102 void period_ms(int ms) {
emilmont 44:24d45a770a51 103 pwmout_period_ms(&_pwm, ms);
emilmont 44:24d45a770a51 104 }
simon.ford@mbed.co.uk 5:62573be585e9 105
emilmont 43:e2ed12d17f06 106 /** Set the PWM period, specified in micro-seconds (int), keeping the duty cycle the same.
rolf.meyer@arm.com 11:1c1ebd0324fa 107 */
emilmont 44:24d45a770a51 108 void period_us(int us) {
emilmont 44:24d45a770a51 109 pwmout_period_us(&_pwm, us);
emilmont 44:24d45a770a51 110 }
simon.ford@mbed.co.uk 5:62573be585e9 111
emilmont 43:e2ed12d17f06 112 /** Set the PWM pulsewidth, specified in seconds (float), keeping the period the same.
rolf.meyer@arm.com 11:1c1ebd0324fa 113 */
emilmont 44:24d45a770a51 114 void pulsewidth(float seconds) {
emilmont 44:24d45a770a51 115 pwmout_pulsewidth(&_pwm, seconds);
emilmont 44:24d45a770a51 116 }
rolf.meyer@arm.com 11:1c1ebd0324fa 117
emilmont 43:e2ed12d17f06 118 /** Set the PWM pulsewidth, specified in milli-seconds (int), keeping the period the same.
rolf.meyer@arm.com 11:1c1ebd0324fa 119 */
emilmont 44:24d45a770a51 120 void pulsewidth_ms(int ms) {
emilmont 44:24d45a770a51 121 pwmout_pulsewidth_ms(&_pwm, ms);
emilmont 44:24d45a770a51 122 }
rolf.meyer@arm.com 11:1c1ebd0324fa 123
emilmont 43:e2ed12d17f06 124 /** Set the PWM pulsewidth, specified in micro-seconds (int), keeping the period the same.
rolf.meyer@arm.com 11:1c1ebd0324fa 125 */
emilmont 44:24d45a770a51 126 void pulsewidth_us(int us) {
emilmont 44:24d45a770a51 127 pwmout_pulsewidth_us(&_pwm, us);
emilmont 44:24d45a770a51 128 }
simon.ford@mbed.co.uk 0:82220227f4fa 129
rolf.meyer@arm.com 11:1c1ebd0324fa 130 #ifdef MBED_OPERATORS
emilmont 43:e2ed12d17f06 131 /** A operator shorthand for write()
rolf.meyer@arm.com 11:1c1ebd0324fa 132 */
emilmont 44:24d45a770a51 133 PwmOut& operator= (float value) {
emilmont 44:24d45a770a51 134 write(value);
emilmont 44:24d45a770a51 135 return *this;
emilmont 44:24d45a770a51 136 }
emilmont 55:d722ed6a4237 137
emilmont 44:24d45a770a51 138 PwmOut& operator= (PwmOut& rhs) {
emilmont 44:24d45a770a51 139 write(rhs.read());
emilmont 44:24d45a770a51 140 return *this;
emilmont 44:24d45a770a51 141 }
emilmont 55:d722ed6a4237 142
emilmont 43:e2ed12d17f06 143 /** An operator shorthand for read()
rolf.meyer@arm.com 11:1c1ebd0324fa 144 */
emilmont 44:24d45a770a51 145 operator float() {
emilmont 44:24d45a770a51 146 return read();
emilmont 44:24d45a770a51 147 }
rolf.meyer@arm.com 11:1c1ebd0324fa 148 #endif
simon.ford@mbed.co.uk 5:62573be585e9 149
simon.ford@mbed.co.uk 0:82220227f4fa 150 protected:
emilmont 44:24d45a770a51 151 pwmout_t _pwm;
simon.ford@mbed.co.uk 0:82220227f4fa 152 };
simon.ford@mbed.co.uk 0:82220227f4fa 153
rolf.meyer@arm.com 11:1c1ebd0324fa 154 } // namespace mbed
simon.ford@mbed.co.uk 0:82220227f4fa 155
simon.ford@mbed.co.uk 1:6b7f447ca868 156 #endif
emilmont 27:7110ebee3484 157
emilmont 27:7110ebee3484 158 #endif