Ruprecht Altenburger / Lib_Misc

Miscellaneous Library, read Encoder etc.

Dependents:   My_Libraries

EncoderCounter.cpp@2:1c5c71a6fac9, 2019-03-06 (annotated)

Committer:
altb
Date:
Wed Mar 06 14:38:04 2019 +0000
Revision:
2:1c5c71a6fac9
Parent:
0:3312872854c4 
.....

Who changed what in which revision?

UserRevisionLine numberNew contents of line
altb 0:3312872854c4 1 /*
altb 0:3312872854c4 2 * EncoderCounter.cpp
altb 0:3312872854c4 3 * Copyright (c) 2017, ZHAW
altb 0:3312872854c4 4 * All rights reserved.
altb 0:3312872854c4 5 */
altb 0:3312872854c4 6
altb 0:3312872854c4 7 #include "EncoderCounter.h"
altb 0:3312872854c4 8
altb 0:3312872854c4 9 using namespace std;
altb 0:3312872854c4 10
altb 0:3312872854c4 11 /**
altb 0:3312872854c4 12 * Creates and initializes the driver to read the quadrature
altb 0:3312872854c4 13 * encoder counter of the STM32 microcontroller.
altb 0:3312872854c4 14 * @param a the input pin for the channel A.
altb 0:3312872854c4 15 * @param b the input pin for the channel B.
altb 0:3312872854c4 16 */
altb 0:3312872854c4 17 EncoderCounter::EncoderCounter(PinName a, PinName b) {
altb 0:3312872854c4 18
altb 0:3312872854c4 19 // check pins
altb 0:3312872854c4 20
altb 0:3312872854c4 21 if ((a == PA_6) && (b == PC_7)) {
altb 0:3312872854c4 22
altb 0:3312872854c4 23 // pinmap OK for TIM3 CH1 and CH2
altb 0:3312872854c4 24
altb 0:3312872854c4 25 TIM = TIM3;
altb 0:3312872854c4 26
altb 0:3312872854c4 27 // configure reset and clock control registers
altb 0:3312872854c4 28
altb 0:3312872854c4 29 RCC->AHB1ENR |= RCC_AHB1ENR_GPIOCEN; // manually enable port C (port A enabled by mbed library)
altb 0:3312872854c4 30
altb 0:3312872854c4 31 // configure general purpose I/O registers
altb 0:3312872854c4 32
altb 0:3312872854c4 33 GPIOA->MODER &= ~GPIO_MODER_MODER6; // reset port A6
altb 0:3312872854c4 34 GPIOA->MODER |= GPIO_MODER_MODER6_1; // set alternate mode of port A6
altb 0:3312872854c4 35 GPIOA->PUPDR &= ~GPIO_PUPDR_PUPDR6; // reset pull-up/pull-down on port A6
altb 0:3312872854c4 36 GPIOA->PUPDR |= GPIO_PUPDR_PUPDR6_1; // set input as pull-down
altb 0:3312872854c4 37 GPIOA->AFR[0] &= ~(0xF << 4*6); // reset alternate function of port A6
altb 0:3312872854c4 38 GPIOA->AFR[0] |= 2 << 4*6; // set alternate funtion 2 of port A6
altb 0:3312872854c4 39
altb 0:3312872854c4 40 GPIOC->MODER &= ~GPIO_MODER_MODER7; // reset port C7
altb 0:3312872854c4 41 GPIOC->MODER |= GPIO_MODER_MODER7_1; // set alternate mode of port C7
altb 0:3312872854c4 42 GPIOC->PUPDR &= ~GPIO_PUPDR_PUPDR7; // reset pull-up/pull-down on port C7
altb 0:3312872854c4 43 GPIOC->PUPDR |= GPIO_PUPDR_PUPDR7_1; // set input as pull-down
altb 0:3312872854c4 44 GPIOC->AFR[0] &= ~0xF0000000; // reset alternate function of port C7
altb 0:3312872854c4 45 GPIOC->AFR[0] |= 2 << 4*7; // set alternate funtion 2 of port C7
altb 0:3312872854c4 46
altb 0:3312872854c4 47 // configure reset and clock control registers
altb 0:3312872854c4 48
altb 0:3312872854c4 49 RCC->APB1RSTR |= RCC_APB1RSTR_TIM3RST; //reset TIM3 controller
altb 0:3312872854c4 50 RCC->APB1RSTR &= ~RCC_APB1RSTR_TIM3RST;
altb 0:3312872854c4 51
altb 0:3312872854c4 52 RCC->APB1ENR |= RCC_APB1ENR_TIM3EN; // TIM3 clock enable
altb 0:3312872854c4 53
altb 0:3312872854c4 54 } else if ((a == PB_6) && (b == PB_7)) {
altb 0:3312872854c4 55
altb 0:3312872854c4 56 // pinmap OK for TIM4 CH1 and CH2
altb 0:3312872854c4 57
altb 0:3312872854c4 58 TIM = TIM4;
altb 0:3312872854c4 59
altb 0:3312872854c4 60 // configure reset and clock control registers
altb 0:3312872854c4 61
altb 0:3312872854c4 62 RCC->AHB1ENR |= RCC_AHB1ENR_GPIOBEN; // manually enable port B (port A enabled by mbed library)
altb 0:3312872854c4 63
altb 0:3312872854c4 64 // configure general purpose I/O registers
altb 0:3312872854c4 65
altb 0:3312872854c4 66 GPIOB->MODER &= ~GPIO_MODER_MODER6; // reset port B6
altb 0:3312872854c4 67 GPIOB->MODER |= GPIO_MODER_MODER6_1; // set alternate mode of port B6
altb 0:3312872854c4 68 GPIOB->PUPDR &= ~GPIO_PUPDR_PUPDR6; // reset pull-up/pull-down on port B6
altb 0:3312872854c4 69 GPIOB->PUPDR |= GPIO_PUPDR_PUPDR6_1; // set input as pull-down
altb 0:3312872854c4 70 GPIOB->AFR[0] &= ~(0xF << 4*6); // reset alternate function of port B6
altb 0:3312872854c4 71 GPIOB->AFR[0] |= 2 << 4*6; // set alternate funtion 2 of port B6
altb 0:3312872854c4 72
altb 0:3312872854c4 73 GPIOB->MODER &= ~GPIO_MODER_MODER7; // reset port B7
altb 0:3312872854c4 74 GPIOB->MODER |= GPIO_MODER_MODER7_1; // set alternate mode of port B7
altb 0:3312872854c4 75 GPIOB->PUPDR &= ~GPIO_PUPDR_PUPDR7; // reset pull-up/pull-down on port B7
altb 0:3312872854c4 76 GPIOB->PUPDR |= GPIO_PUPDR_PUPDR7_1; // set input as pull-down
altb 0:3312872854c4 77 GPIOB->AFR[0] &= ~0xF0000000; // reset alternate function of port B7
altb 0:3312872854c4 78 GPIOB->AFR[0] |= 2 << 4*7; // set alternate funtion 2 of port B7
altb 0:3312872854c4 79
altb 0:3312872854c4 80 // configure reset and clock control registers
altb 0:3312872854c4 81
altb 0:3312872854c4 82 RCC->APB1RSTR |= RCC_APB1RSTR_TIM4RST; //reset TIM4 controller
altb 0:3312872854c4 83 RCC->APB1RSTR &= ~RCC_APB1RSTR_TIM4RST;
altb 0:3312872854c4 84
altb 0:3312872854c4 85 RCC->APB1ENR |= RCC_APB1ENR_TIM4EN; // TIM4 clock enable
altb 0:3312872854c4 86
altb 0:3312872854c4 87 } else {
altb 0:3312872854c4 88
altb 0:3312872854c4 89 printf("pinmap not found for peripheral\n");
altb 0:3312872854c4 90 }
altb 0:3312872854c4 91
altb 0:3312872854c4 92 // configure general purpose timer 3 or 4
altb 0:3312872854c4 93
altb 0:3312872854c4 94 TIM->CR1 = 0x0000; // counter disable
altb 0:3312872854c4 95 TIM->CR2 = 0x0000; // reset master mode selection
altb 0:3312872854c4 96 TIM->SMCR = TIM_SMCR_SMS_1 | TIM_SMCR_SMS_0; // counting on both TI1 & TI2 edges
altb 0:3312872854c4 97 TIM->CCMR1 = TIM_CCMR1_CC2S_0 | TIM_CCMR1_CC1S_0;
altb 0:3312872854c4 98 TIM->CCMR2 = 0x0000; // reset capture mode register 2
altb 0:3312872854c4 99 TIM->CCER = TIM_CCER_CC2E | TIM_CCER_CC1E;
altb 0:3312872854c4 100 TIM->CNT = 0x0000; // reset counter value
altb 0:3312872854c4 101 TIM->ARR = 0xFFFF; // auto reload register
altb 0:3312872854c4 102 TIM->CR1 = TIM_CR1_CEN; // counter enable
altb 0:3312872854c4 103 }
altb 0:3312872854c4 104
altb 0:3312872854c4 105 EncoderCounter::~EncoderCounter() {}
altb 0:3312872854c4 106
altb 0:3312872854c4 107 /**
altb 0:3312872854c4 108 * Resets the counter value to zero.
altb 0:3312872854c4 109 */
altb 0:3312872854c4 110 void EncoderCounter::reset() {
altb 0:3312872854c4 111
altb 0:3312872854c4 112 TIM->CNT = 0x0000;
altb 0:3312872854c4 113 }
altb 0:3312872854c4 114
altb 0:3312872854c4 115 /**
altb 0:3312872854c4 116 * Resets the counter value to a given offset value.
altb 0:3312872854c4 117 * @param offset the offset value to reset the counter to.
altb 0:3312872854c4 118 */
altb 0:3312872854c4 119 void EncoderCounter::reset(short offset) {
altb 0:3312872854c4 120
altb 0:3312872854c4 121 TIM->CNT = -offset;
altb 0:3312872854c4 122 }
altb 0:3312872854c4 123
altb 0:3312872854c4 124 /**
altb 0:3312872854c4 125 * Reads the quadrature encoder counter value.
altb 0:3312872854c4 126 * @return the quadrature encoder counter as a signed 16-bit integer value.
altb 0:3312872854c4 127 */
altb 0:3312872854c4 128 short EncoderCounter::read() {
altb 0:3312872854c4 129
altb 0:3312872854c4 130 return (short)(-TIM->CNT);
altb 0:3312872854c4 131 }
altb 0:3312872854c4 132
altb 0:3312872854c4 133 /**
altb 0:3312872854c4 134 * The empty operator is a shorthand notation of the <code>read()</code> method.
altb 0:3312872854c4 135 */
altb 0:3312872854c4 136 EncoderCounter::operator short() {
altb 0:3312872854c4 137
altb 0:3312872854c4 138 return read();
altb 0:3312872854c4 139 }