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EncoderCounter.cpp@11:78e723ede0c6, 2019-02-25 (annotated)
- Committer:
- altb
- Date:
- Mon Feb 25 09:47:04 2019 +0000
- Revision:
- 11:78e723ede0c6
- Parent:
- 0:d784b08f51ff
2018
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
altb | 0:d784b08f51ff | 1 | /* |
altb | 0:d784b08f51ff | 2 | * EncoderCounter.cpp |
altb | 0:d784b08f51ff | 3 | * Copyright (c) 2017, ZHAW |
altb | 0:d784b08f51ff | 4 | * All rights reserved. |
altb | 0:d784b08f51ff | 5 | */ |
altb | 0:d784b08f51ff | 6 | |
altb | 0:d784b08f51ff | 7 | #include "EncoderCounter.h" |
altb | 0:d784b08f51ff | 8 | |
altb | 0:d784b08f51ff | 9 | using namespace std; |
altb | 0:d784b08f51ff | 10 | |
altb | 0:d784b08f51ff | 11 | /** |
altb | 0:d784b08f51ff | 12 | * Creates and initializes the driver to read the quadrature |
altb | 0:d784b08f51ff | 13 | * encoder counter of the STM32 microcontroller. |
altb | 0:d784b08f51ff | 14 | * @param a the input pin for the channel A. |
altb | 0:d784b08f51ff | 15 | * @param b the input pin for the channel B. |
altb | 0:d784b08f51ff | 16 | */ |
altb | 0:d784b08f51ff | 17 | EncoderCounter::EncoderCounter(PinName a, PinName b) { |
altb | 0:d784b08f51ff | 18 | |
altb | 0:d784b08f51ff | 19 | // check pins |
altb | 0:d784b08f51ff | 20 | |
altb | 0:d784b08f51ff | 21 | if ((a == PA_6) && (b == PC_7)) { |
altb | 0:d784b08f51ff | 22 | |
altb | 0:d784b08f51ff | 23 | // pinmap OK for TIM3 CH1 and CH2 |
altb | 0:d784b08f51ff | 24 | |
altb | 0:d784b08f51ff | 25 | TIM = TIM3; |
altb | 0:d784b08f51ff | 26 | |
altb | 0:d784b08f51ff | 27 | // configure reset and clock control registers |
altb | 0:d784b08f51ff | 28 | |
altb | 0:d784b08f51ff | 29 | RCC->AHB1ENR |= RCC_AHB1ENR_GPIOCEN; // manually enable port C (port A enabled by mbed library) |
altb | 0:d784b08f51ff | 30 | |
altb | 0:d784b08f51ff | 31 | // configure general purpose I/O registers |
altb | 0:d784b08f51ff | 32 | |
altb | 0:d784b08f51ff | 33 | GPIOA->MODER &= ~GPIO_MODER_MODER6; // reset port A6 |
altb | 0:d784b08f51ff | 34 | GPIOA->MODER |= GPIO_MODER_MODER6_1; // set alternate mode of port A6 |
altb | 0:d784b08f51ff | 35 | GPIOA->PUPDR &= ~GPIO_PUPDR_PUPDR6; // reset pull-up/pull-down on port A6 |
altb | 0:d784b08f51ff | 36 | GPIOA->PUPDR |= GPIO_PUPDR_PUPDR6_1; // set input as pull-down |
altb | 0:d784b08f51ff | 37 | GPIOA->AFR[0] &= ~(0xF << 4*6); // reset alternate function of port A6 |
altb | 0:d784b08f51ff | 38 | GPIOA->AFR[0] |= 2 << 4*6; // set alternate funtion 2 of port A6 |
altb | 0:d784b08f51ff | 39 | |
altb | 0:d784b08f51ff | 40 | GPIOC->MODER &= ~GPIO_MODER_MODER7; // reset port C7 |
altb | 0:d784b08f51ff | 41 | GPIOC->MODER |= GPIO_MODER_MODER7_1; // set alternate mode of port C7 |
altb | 0:d784b08f51ff | 42 | GPIOC->PUPDR &= ~GPIO_PUPDR_PUPDR7; // reset pull-up/pull-down on port C7 |
altb | 0:d784b08f51ff | 43 | GPIOC->PUPDR |= GPIO_PUPDR_PUPDR7_1; // set input as pull-down |
altb | 0:d784b08f51ff | 44 | GPIOC->AFR[0] &= ~0xF0000000; // reset alternate function of port C7 |
altb | 0:d784b08f51ff | 45 | GPIOC->AFR[0] |= 2 << 4*7; // set alternate funtion 2 of port C7 |
altb | 0:d784b08f51ff | 46 | |
altb | 0:d784b08f51ff | 47 | // configure reset and clock control registers |
altb | 0:d784b08f51ff | 48 | |
altb | 0:d784b08f51ff | 49 | RCC->APB1RSTR |= RCC_APB1RSTR_TIM3RST; //reset TIM3 controller |
altb | 0:d784b08f51ff | 50 | RCC->APB1RSTR &= ~RCC_APB1RSTR_TIM3RST; |
altb | 0:d784b08f51ff | 51 | |
altb | 0:d784b08f51ff | 52 | RCC->APB1ENR |= RCC_APB1ENR_TIM3EN; // TIM3 clock enable |
altb | 0:d784b08f51ff | 53 | |
altb | 0:d784b08f51ff | 54 | } else if ((a == PB_6) && (b == PB_7)) { |
altb | 0:d784b08f51ff | 55 | |
altb | 0:d784b08f51ff | 56 | // pinmap OK for TIM4 CH1 and CH2 |
altb | 0:d784b08f51ff | 57 | |
altb | 0:d784b08f51ff | 58 | TIM = TIM4; |
altb | 0:d784b08f51ff | 59 | |
altb | 0:d784b08f51ff | 60 | // configure reset and clock control registers |
altb | 0:d784b08f51ff | 61 | |
altb | 0:d784b08f51ff | 62 | RCC->AHB1ENR |= RCC_AHB1ENR_GPIOBEN; // manually enable port B (port A enabled by mbed library) |
altb | 0:d784b08f51ff | 63 | |
altb | 0:d784b08f51ff | 64 | // configure general purpose I/O registers |
altb | 0:d784b08f51ff | 65 | |
altb | 0:d784b08f51ff | 66 | GPIOB->MODER &= ~GPIO_MODER_MODER6; // reset port B6 |
altb | 0:d784b08f51ff | 67 | GPIOB->MODER |= GPIO_MODER_MODER6_1; // set alternate mode of port B6 |
altb | 0:d784b08f51ff | 68 | GPIOB->PUPDR &= ~GPIO_PUPDR_PUPDR6; // reset pull-up/pull-down on port B6 |
altb | 0:d784b08f51ff | 69 | GPIOB->PUPDR |= GPIO_PUPDR_PUPDR6_1; // set input as pull-down |
altb | 0:d784b08f51ff | 70 | GPIOB->AFR[0] &= ~(0xF << 4*6); // reset alternate function of port B6 |
altb | 0:d784b08f51ff | 71 | GPIOB->AFR[0] |= 2 << 4*6; // set alternate funtion 2 of port B6 |
altb | 0:d784b08f51ff | 72 | |
altb | 0:d784b08f51ff | 73 | GPIOB->MODER &= ~GPIO_MODER_MODER7; // reset port B7 |
altb | 0:d784b08f51ff | 74 | GPIOB->MODER |= GPIO_MODER_MODER7_1; // set alternate mode of port B7 |
altb | 0:d784b08f51ff | 75 | GPIOB->PUPDR &= ~GPIO_PUPDR_PUPDR7; // reset pull-up/pull-down on port B7 |
altb | 0:d784b08f51ff | 76 | GPIOB->PUPDR |= GPIO_PUPDR_PUPDR7_1; // set input as pull-down |
altb | 0:d784b08f51ff | 77 | GPIOB->AFR[0] &= ~0xF0000000; // reset alternate function of port B7 |
altb | 0:d784b08f51ff | 78 | GPIOB->AFR[0] |= 2 << 4*7; // set alternate funtion 2 of port B7 |
altb | 0:d784b08f51ff | 79 | |
altb | 0:d784b08f51ff | 80 | // configure reset and clock control registers |
altb | 0:d784b08f51ff | 81 | |
altb | 0:d784b08f51ff | 82 | RCC->APB1RSTR |= RCC_APB1RSTR_TIM4RST; //reset TIM4 controller |
altb | 0:d784b08f51ff | 83 | RCC->APB1RSTR &= ~RCC_APB1RSTR_TIM4RST; |
altb | 0:d784b08f51ff | 84 | |
altb | 0:d784b08f51ff | 85 | RCC->APB1ENR |= RCC_APB1ENR_TIM4EN; // TIM4 clock enable |
altb | 0:d784b08f51ff | 86 | |
altb | 0:d784b08f51ff | 87 | } else { |
altb | 0:d784b08f51ff | 88 | |
altb | 0:d784b08f51ff | 89 | printf("pinmap not found for peripheral\n"); |
altb | 0:d784b08f51ff | 90 | } |
altb | 0:d784b08f51ff | 91 | |
altb | 0:d784b08f51ff | 92 | // configure general purpose timer 3 or 4 |
altb | 0:d784b08f51ff | 93 | |
altb | 0:d784b08f51ff | 94 | TIM->CR1 = 0x0000; // counter disable |
altb | 0:d784b08f51ff | 95 | TIM->CR2 = 0x0000; // reset master mode selection |
altb | 0:d784b08f51ff | 96 | TIM->SMCR = TIM_SMCR_SMS_1 | TIM_SMCR_SMS_0; // counting on both TI1 & TI2 edges |
altb | 0:d784b08f51ff | 97 | TIM->CCMR1 = TIM_CCMR1_CC2S_0 | TIM_CCMR1_CC1S_0; |
altb | 0:d784b08f51ff | 98 | TIM->CCMR2 = 0x0000; // reset capture mode register 2 |
altb | 0:d784b08f51ff | 99 | TIM->CCER = TIM_CCER_CC2E | TIM_CCER_CC1E; |
altb | 0:d784b08f51ff | 100 | TIM->CNT = 0x0000; // reset counter value |
altb | 0:d784b08f51ff | 101 | TIM->ARR = 0xFFFF; // auto reload register |
altb | 0:d784b08f51ff | 102 | TIM->CR1 = TIM_CR1_CEN; // counter enable |
altb | 0:d784b08f51ff | 103 | } |
altb | 0:d784b08f51ff | 104 | |
altb | 0:d784b08f51ff | 105 | EncoderCounter::~EncoderCounter() {} |
altb | 0:d784b08f51ff | 106 | |
altb | 0:d784b08f51ff | 107 | /** |
altb | 0:d784b08f51ff | 108 | * Resets the counter value to zero. |
altb | 0:d784b08f51ff | 109 | */ |
altb | 0:d784b08f51ff | 110 | void EncoderCounter::reset() { |
altb | 0:d784b08f51ff | 111 | |
altb | 0:d784b08f51ff | 112 | TIM->CNT = 0x0000; |
altb | 0:d784b08f51ff | 113 | } |
altb | 0:d784b08f51ff | 114 | |
altb | 0:d784b08f51ff | 115 | /** |
altb | 0:d784b08f51ff | 116 | * Resets the counter value to a given offset value. |
altb | 0:d784b08f51ff | 117 | * @param offset the offset value to reset the counter to. |
altb | 0:d784b08f51ff | 118 | */ |
altb | 0:d784b08f51ff | 119 | void EncoderCounter::reset(short offset) { |
altb | 0:d784b08f51ff | 120 | |
altb | 0:d784b08f51ff | 121 | TIM->CNT = -offset; |
altb | 0:d784b08f51ff | 122 | } |
altb | 0:d784b08f51ff | 123 | |
altb | 0:d784b08f51ff | 124 | /** |
altb | 0:d784b08f51ff | 125 | * Reads the quadrature encoder counter value. |
altb | 0:d784b08f51ff | 126 | * @return the quadrature encoder counter as a signed 16-bit integer value. |
altb | 0:d784b08f51ff | 127 | */ |
altb | 0:d784b08f51ff | 128 | short EncoderCounter::read() { |
altb | 0:d784b08f51ff | 129 | |
altb | 0:d784b08f51ff | 130 | return (short)(-TIM->CNT); |
altb | 0:d784b08f51ff | 131 | } |
altb | 0:d784b08f51ff | 132 | |
altb | 0:d784b08f51ff | 133 | /** |
altb | 0:d784b08f51ff | 134 | * The empty operator is a shorthand notation of the <code>read()</code> method. |
altb | 0:d784b08f51ff | 135 | */ |
altb | 0:d784b08f51ff | 136 | EncoderCounter::operator short() { |
altb | 0:d784b08f51ff | 137 | |
altb | 0:d784b08f51ff | 138 | return read(); |
altb | 0:d784b08f51ff | 139 | } |