Giles Barton-Owen / PWMAverage

A PWM/duty cycle measurement library using Timer2

Dependents:   PWMAverage_test pwm_duty_measurement

PWMAverage.cpp@0:5da51898a166, 2012-08-29 (annotated)

Committer:
p07gbar
Date:
Wed Aug 29 11:25:55 2012 +0000
Revision:
0:5da51898a166
Child:
1:34a9269390d9
Initial commit

Who changed what in which revision?

UserRevisionLine numberNew contents of line
p07gbar 0:5da51898a166 1 #include "PWMAverage.h"
p07gbar 0:5da51898a166 2
p07gbar 0:5da51898a166 3 #define PWMA_PCLK 96000000
p07gbar 0:5da51898a166 4
p07gbar 0:5da51898a166 5
p07gbar 0:5da51898a166 6 PWMAverage * PWMAverage::instance;
p07gbar 0:5da51898a166 7
p07gbar 0:5da51898a166 8
p07gbar 0:5da51898a166 9 void PWMAverage::_tisr()
p07gbar 0:5da51898a166 10 {
p07gbar 0:5da51898a166 11 //printf(".");
p07gbar 0:5da51898a166 12 int cr0 = LPC_TIM2->CR0;
p07gbar 0:5da51898a166 13 int cr1 = LPC_TIM2->CR1;
p07gbar 0:5da51898a166 14
p07gbar 0:5da51898a166 15 LPC_TIM2->IR = 0x3F;
p07gbar 0:5da51898a166 16
p07gbar 0:5da51898a166 17 LPC_TIM2->TCR = 3;
p07gbar 0:5da51898a166 18 LPC_TIM2->TCR = 1;
p07gbar 0:5da51898a166 19
p07gbar 0:5da51898a166 20 //LPC_NVIC->ICPR0 |= (1<<3)
p07gbar 0:5da51898a166 21
p07gbar 0:5da51898a166 22 if(!instance->starting)
p07gbar 0:5da51898a166 23 {
p07gbar 0:5da51898a166 24 instance->total += cr1 + 82;
p07gbar 0:5da51898a166 25 instance->totalup += cr0 + 82;
p07gbar 0:5da51898a166 26 instance->count_++;
p07gbar 0:5da51898a166 27 }
p07gbar 0:5da51898a166 28 else instance->starting = false;
p07gbar 0:5da51898a166 29
p07gbar 0:5da51898a166 30 }
p07gbar 0:5da51898a166 31
p07gbar 0:5da51898a166 32 PWMAverage::PWMAverage(PinName cap0, PinName cap1)
p07gbar 0:5da51898a166 33 {
p07gbar 0:5da51898a166 34 printf("\n\rPWMAverage\n\r");
p07gbar 0:5da51898a166 35 prescaler_point = 0x0;
p07gbar 0:5da51898a166 36 configure();
p07gbar 0:5da51898a166 37 stop();
p07gbar 0:5da51898a166 38
p07gbar 0:5da51898a166 39 printf("Done config\n\r");
p07gbar 0:5da51898a166 40
p07gbar 0:5da51898a166 41 timeMult = (1/PWMA_PCLK)*(prescaler_point+1);
p07gbar 0:5da51898a166 42 timeDiv = PWMA_PCLK/(prescaler_point+1);
p07gbar 0:5da51898a166 43 instance = this;
p07gbar 0:5da51898a166 44 }
p07gbar 0:5da51898a166 45
p07gbar 0:5da51898a166 46 void PWMAverage::reset()
p07gbar 0:5da51898a166 47 {
p07gbar 0:5da51898a166 48 count_ = 0;
p07gbar 0:5da51898a166 49 total = 0;
p07gbar 0:5da51898a166 50 totalup = 0;
p07gbar 0:5da51898a166 51 LPC_TIM2->TCR = 2;
p07gbar 0:5da51898a166 52 LPC_TIM2->TCR = 0;
p07gbar 0:5da51898a166 53 }
p07gbar 0:5da51898a166 54
p07gbar 0:5da51898a166 55 void PWMAverage::start()
p07gbar 0:5da51898a166 56 {
p07gbar 0:5da51898a166 57 //reset();
p07gbar 0:5da51898a166 58 starting = true;
p07gbar 0:5da51898a166 59 enable(true);
p07gbar 0:5da51898a166 60 NVIC_EnableIRQ(TIMER2_IRQn);
p07gbar 0:5da51898a166 61 }
p07gbar 0:5da51898a166 62
p07gbar 0:5da51898a166 63 void PWMAverage::stop()
p07gbar 0:5da51898a166 64 {
p07gbar 0:5da51898a166 65 enable(false);
p07gbar 0:5da51898a166 66 NVIC_DisableIRQ(TIMER2_IRQn);
p07gbar 0:5da51898a166 67 }
p07gbar 0:5da51898a166 68
p07gbar 0:5da51898a166 69 float PWMAverage::read()
p07gbar 0:5da51898a166 70 {
p07gbar 0:5da51898a166 71 if(period() != 0) return float(avg_up()/period());
p07gbar 0:5da51898a166 72 else return 0;
p07gbar 0:5da51898a166 73 }
p07gbar 0:5da51898a166 74
p07gbar 0:5da51898a166 75 double PWMAverage::avg_up()
p07gbar 0:5da51898a166 76 {
p07gbar 0:5da51898a166 77 if(count_!= 0) return (double(totalup)/timeDiv)/double(count_);
p07gbar 0:5da51898a166 78 else return 0;
p07gbar 0:5da51898a166 79
p07gbar 0:5da51898a166 80 }
p07gbar 0:5da51898a166 81
p07gbar 0:5da51898a166 82 float PWMAverage::avg_UP()
p07gbar 0:5da51898a166 83 {
p07gbar 0:5da51898a166 84 if(count_!= 0) return float((double(totalup)/timeDiv)/double(count_));
p07gbar 0:5da51898a166 85 else return 0;
p07gbar 0:5da51898a166 86 }
p07gbar 0:5da51898a166 87
p07gbar 0:5da51898a166 88 double PWMAverage::avg_down()
p07gbar 0:5da51898a166 89 {
p07gbar 0:5da51898a166 90 if(count_!= 0) return (double(total-totalup)/timeDiv)/double(count_);
p07gbar 0:5da51898a166 91 else return 0;
p07gbar 0:5da51898a166 92 }
p07gbar 0:5da51898a166 93
p07gbar 0:5da51898a166 94 double PWMAverage::period()
p07gbar 0:5da51898a166 95 {
p07gbar 0:5da51898a166 96 if(count_!= 0) return (double(total)/timeDiv)/double(count_);
p07gbar 0:5da51898a166 97 else return 0;
p07gbar 0:5da51898a166 98 }
p07gbar 0:5da51898a166 99
p07gbar 0:5da51898a166 100 int PWMAverage::count()
p07gbar 0:5da51898a166 101 {
p07gbar 0:5da51898a166 102 return count_;
p07gbar 0:5da51898a166 103 }
p07gbar 0:5da51898a166 104
p07gbar 0:5da51898a166 105 void PWMAverage::enable(bool yn)
p07gbar 0:5da51898a166 106 {
p07gbar 0:5da51898a166 107 LPC_TIM2->TCR = yn;
p07gbar 0:5da51898a166 108 }
p07gbar 0:5da51898a166 109
p07gbar 0:5da51898a166 110 void PWMAverage::configure()
p07gbar 0:5da51898a166 111 {
p07gbar 0:5da51898a166 112 //Power Periferal
p07gbar 0:5da51898a166 113
p07gbar 0:5da51898a166 114 LPC_SC->PCONP |= (1<<22);
p07gbar 0:5da51898a166 115
p07gbar 0:5da51898a166 116 //Setup Pins
p07gbar 0:5da51898a166 117
p07gbar 0:5da51898a166 118 LPC_PINCON->PINSEL0 |= (0x3<<8);
p07gbar 0:5da51898a166 119 LPC_PINCON->PINSEL0 |= (0x3<<10);
p07gbar 0:5da51898a166 120
p07gbar 0:5da51898a166 121 //Setup clock source
p07gbar 0:5da51898a166 122
p07gbar 0:5da51898a166 123 LPC_SC->PCLKSEL1 |= (0x1<<12);
p07gbar 0:5da51898a166 124
p07gbar 0:5da51898a166 125 //Setup PC
p07gbar 0:5da51898a166 126
p07gbar 0:5da51898a166 127 LPC_TIM2->PR = prescaler_point;
p07gbar 0:5da51898a166 128
p07gbar 0:5da51898a166 129 //Setup CAP0 - Store on fall
p07gbar 0:5da51898a166 130
p07gbar 0:5da51898a166 131 LPC_TIM2->CCR |= 0x2;
p07gbar 0:5da51898a166 132
p07gbar 0:5da51898a166 133 //Setup CAP1 - Store on rise, interrupt
p07gbar 0:5da51898a166 134
p07gbar 0:5da51898a166 135 LPC_TIM2->CCR |= 0x5<<3;
p07gbar 0:5da51898a166 136
p07gbar 0:5da51898a166 137 //Setup IRQs
p07gbar 0:5da51898a166 138 NVIC_DisableIRQ(TIMER2_IRQn);
p07gbar 0:5da51898a166 139 NVIC_SetVector(TIMER2_IRQn, (uint32_t)&_tisr);
p07gbar 0:5da51898a166 140 NVIC_EnableIRQ(TIMER2_IRQn);
p07gbar 0:5da51898a166 141 //
p07gbar 0:5da51898a166 142 }