Giles Barton-Owen / PWMAverage

A PWM/duty cycle measurement library using Timer2

Dependents:   PWMAverage_test pwm_duty_measurement

PWMAverage.h@4:a3d3a60e30b7, 2012-08-29 (annotated)

Committer:
p07gbar
Date:
Wed Aug 29 12:02:45 2012 +0000
Revision:
4:a3d3a60e30b7
Parent:
2:449ea283d634 
Working

Who changed what in which revision?

UserRevisionLine numberNew contents of line
p07gbar 0:5da51898a166 1 /**
p07gbar 0:5da51898a166 2 * @author Giles Barton-Owen
p07gbar 0:5da51898a166 3 *
p07gbar 0:5da51898a166 4 * @section LICENSE
p07gbar 0:5da51898a166 5 *
p07gbar 0:5da51898a166 6 * Copyright (c) 2011 mbed
p07gbar 0:5da51898a166 7 *
p07gbar 0:5da51898a166 8 * Permission is hereby granted, free of charge, to any person obtaining a copy
p07gbar 0:5da51898a166 9 * of this software and associated documentation files (the "Software"), to deal
p07gbar 0:5da51898a166 10 * in the Software without restriction, including without limitation the rights
p07gbar 0:5da51898a166 11 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
p07gbar 0:5da51898a166 12 * copies of the Software, and to permit persons to whom the Software is
p07gbar 0:5da51898a166 13 * furnished to do so, subject to the following conditions:
p07gbar 0:5da51898a166 14 *
p07gbar 0:5da51898a166 15 * The above copyright notice and this permission notice shall be included in
p07gbar 0:5da51898a166 16 * all copies or substantial portions of the Software.
p07gbar 0:5da51898a166 17 *
p07gbar 0:5da51898a166 18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
p07gbar 0:5da51898a166 19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
p07gbar 0:5da51898a166 20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
p07gbar 0:5da51898a166 21 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
p07gbar 0:5da51898a166 22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
p07gbar 0:5da51898a166 23 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
p07gbar 0:5da51898a166 24 * THE SOFTWARE.
p07gbar 0:5da51898a166 25 *
p07gbar 0:5da51898a166 26 * @section DESCRIPTION
p07gbar 0:5da51898a166 27 * PWM/Duty cycle measurement library using Timer2: library h file for NXP LPC1768
p07gbar 0:5da51898a166 28 *
p07gbar 0:5da51898a166 29 */
p07gbar 0:5da51898a166 30
p07gbar 0:5da51898a166 31 #ifndef PWMAVERAGE_H
p07gbar 0:5da51898a166 32 #define PWMAVERAGE_H
p07gbar 0:5da51898a166 33 #include "mbed.h"
p07gbar 0:5da51898a166 34
p07gbar 0:5da51898a166 35
p07gbar 0:5da51898a166 36 /** A class for measuring PWM/Duty cycle of a signal connected to pins 30 and 29
p07gbar 0:5da51898a166 37 *
p07gbar 4:a3d3a60e30b7 38 <<<<<<< local
p07gbar 2:449ea283d634 39 * Example:
p07gbar 4:a3d3a60e30b7 40 =======
p07gbar 4:a3d3a60e30b7 41 *
p07gbar 4:a3d3a60e30b7 42 >>>>>>> other
p07gbar 1:34a9269390d9 43 * @code
p07gbar 1:34a9269390d9 44 * // Measure and print the average duty cycle of a signal connected to p29 and p30 (together) while the button (p16) is pulled high
p07gbar 1:34a9269390d9 45 *
p07gbar 1:34a9269390d9 46 * #include "mbed.h"
p07gbar 1:34a9269390d9 47 * #include "PWMAverage.h"
p07gbar 1:34a9269390d9 48 *
p07gbar 1:34a9269390d9 49 * DigitalOut myled(LED1);
p07gbar 1:34a9269390d9 50 *
p07gbar 1:34a9269390d9 51 * PWMAverage pa(p29,p30);
p07gbar 1:34a9269390d9 52 *
p07gbar 1:34a9269390d9 53 * DigitalIn button (p16);
p07gbar 1:34a9269390d9 54 *
p07gbar 1:34a9269390d9 55 * Timer tmr;
p07gbar 1:34a9269390d9 56 *
p07gbar 1:34a9269390d9 57 * int main()
p07gbar 1:34a9269390d9 58 * {
p07gbar 1:34a9269390d9 59 * button.mode(PullDown);
p07gbar 1:34a9269390d9 60 * while(1)
p07gbar 1:34a9269390d9 61 * {
p07gbar 1:34a9269390d9 62 * pa.reset();
p07gbar 1:34a9269390d9 63 *
p07gbar 1:34a9269390d9 64 * while (!button) {}
p07gbar 1:34a9269390d9 65 * pa.start();
p07gbar 1:34a9269390d9 66 * tmr.start();
p07gbar 1:34a9269390d9 67 * myled=1;
p07gbar 1:34a9269390d9 68 *
p07gbar 1:34a9269390d9 69 * while (button) {}
p07gbar 1:34a9269390d9 70 * pa.stop();
p07gbar 1:34a9269390d9 71 * tmr.stop();
p07gbar 1:34a9269390d9 72 * myled=0;
p07gbar 1:34a9269390d9 73 *
p07gbar 1:34a9269390d9 74 * printf("Average dudy cycle over %d us was %.4f\n\r",tmr.read_us(),pa.read());
p07gbar 1:34a9269390d9 75 * }
p07gbar 1:34a9269390d9 76 * }
p07gbar 1:34a9269390d9 77 * @endcode
p07gbar 0:5da51898a166 78 */
p07gbar 0:5da51898a166 79 class PWMAverage
p07gbar 0:5da51898a166 80 {
p07gbar 0:5da51898a166 81 public:
p07gbar 0:5da51898a166 82 /** Create a PWMAverage object
p07gbar 0:5da51898a166 83 *
p07gbar 0:5da51898a166 84 * @param cap0 Pin connected to signal (ignored in program)
p07gbar 0:5da51898a166 85 * @param cap1 Pin connected to signal (ignored in program)
p07gbar 0:5da51898a166 86 */
p07gbar 0:5da51898a166 87 PWMAverage(PinName cap0, PinName cap1);
p07gbar 0:5da51898a166 88
p07gbar 0:5da51898a166 89 /** Reset the counters and values
p07gbar 0:5da51898a166 90 */
p07gbar 0:5da51898a166 91 void reset();
p07gbar 0:5da51898a166 92 /** Start the timer
p07gbar 0:5da51898a166 93 */
p07gbar 0:5da51898a166 94 void start();
p07gbar 0:5da51898a166 95 /** Stop the timer
p07gbar 0:5da51898a166 96 */
p07gbar 0:5da51898a166 97 void stop();
p07gbar 0:5da51898a166 98 /** Read the duty cycle measured
p07gbar 0:5da51898a166 99 * @returns The Duty cycle
p07gbar 0:5da51898a166 100 */
p07gbar 0:5da51898a166 101 float read();
p07gbar 0:5da51898a166 102 /** Read the average length of time the signal was high per cycle in seconds
p07gbar 0:5da51898a166 103 * @returns The Length of time the signal was high per cycle in seconds
p07gbar 0:5da51898a166 104 */
p07gbar 0:5da51898a166 105 double avg_up();
p07gbar 0:5da51898a166 106 /** Read the average length of time the signal was high per cycle in seconds
p07gbar 0:5da51898a166 107 * @returns The Length of time the signal was high per cycle in seconds
p07gbar 0:5da51898a166 108 */
p07gbar 0:5da51898a166 109 float avg_UP();
p07gbar 0:5da51898a166 110 /** Read the average length of time the signal was low per cycle in seconds
p07gbar 0:5da51898a166 111 * @returns The Length of time the signal was low per cycle in seconds
p07gbar 0:5da51898a166 112 */
p07gbar 0:5da51898a166 113 double avg_down();
p07gbar 0:5da51898a166 114 /** Read the average period in seconds
p07gbar 0:5da51898a166 115 * @returns The Period
p07gbar 0:5da51898a166 116 */
p07gbar 0:5da51898a166 117 double period();
p07gbar 0:5da51898a166 118 /** Read the number of cycles counted over
p07gbar 0:5da51898a166 119 * @returns The number of cycles
p07gbar 0:5da51898a166 120 */
p07gbar 0:5da51898a166 121 int count();
p07gbar 0:5da51898a166 122
p07gbar 1:34a9269390d9 123 private:
p07gbar 1:34a9269390d9 124
p07gbar 1:34a9269390d9 125 static void _tisr();
p07gbar 1:34a9269390d9 126 static PWMAverage * instance;
p07gbar 1:34a9269390d9 127 void enable(bool yn);
p07gbar 1:34a9269390d9 128 void configure();
p07gbar 1:34a9269390d9 129
p07gbar 0:5da51898a166 130 long count_;
p07gbar 0:5da51898a166 131 long totalup;
p07gbar 0:5da51898a166 132 long total;
p07gbar 0:5da51898a166 133
p07gbar 0:5da51898a166 134 double timeMult;
p07gbar 0:5da51898a166 135
p07gbar 0:5da51898a166 136 double timeDiv;
p07gbar 0:5da51898a166 137
p07gbar 0:5da51898a166 138 bool running;
p07gbar 0:5da51898a166 139 bool starting;
p07gbar 0:5da51898a166 140
p07gbar 0:5da51898a166 141 uint32_t prescaler_point;
p07gbar 0:5da51898a166 142
p07gbar 0:5da51898a166 143 };
p07gbar 0:5da51898a166 144
p07gbar 0:5da51898a166 145
p07gbar 0:5da51898a166 146 #endif