2nd try
EncoderCounter.cpp
- Committer:
- altb2
- Date:
- 2019-03-07
- Revision:
- 0:72b60c5271cc
File content as of revision 0:72b60c5271cc:
/* * EncoderCounter.cpp * Copyright (c) 2017, ZHAW * All rights reserved. */ #include "EncoderCounter.h" using namespace std; /** * Creates and initializes the driver to read the quadrature * encoder counter of the STM32 microcontroller. * @param a the input pin for the channel A. * @param b the input pin for the channel B. */ EncoderCounter::EncoderCounter(PinName a, PinName b) { // check pins if ((a == PA_6) && (b == PC_7)) { // pinmap OK for TIM3 CH1 and CH2 TIM = TIM3; // configure reset and clock control registers RCC->AHB1ENR |= RCC_AHB1ENR_GPIOCEN; // manually enable port C (port A enabled by mbed library) // configure general purpose I/O registers GPIOA->MODER &= ~GPIO_MODER_MODER6; // reset port A6 GPIOA->MODER |= GPIO_MODER_MODER6_1; // set alternate mode of port A6 GPIOA->PUPDR &= ~GPIO_PUPDR_PUPDR6; // reset pull-up/pull-down on port A6 GPIOA->PUPDR |= GPIO_PUPDR_PUPDR6_1; // set input as pull-down GPIOA->AFR[0] &= ~(0xF << 4*6); // reset alternate function of port A6 GPIOA->AFR[0] |= 2 << 4*6; // set alternate funtion 2 of port A6 GPIOC->MODER &= ~GPIO_MODER_MODER7; // reset port C7 GPIOC->MODER |= GPIO_MODER_MODER7_1; // set alternate mode of port C7 GPIOC->PUPDR &= ~GPIO_PUPDR_PUPDR7; // reset pull-up/pull-down on port C7 GPIOC->PUPDR |= GPIO_PUPDR_PUPDR7_1; // set input as pull-down GPIOC->AFR[0] &= ~0xF0000000; // reset alternate function of port C7 GPIOC->AFR[0] |= 2 << 4*7; // set alternate funtion 2 of port C7 // configure reset and clock control registers RCC->APB1RSTR |= RCC_APB1RSTR_TIM3RST; //reset TIM3 controller RCC->APB1RSTR &= ~RCC_APB1RSTR_TIM3RST; RCC->APB1ENR |= RCC_APB1ENR_TIM3EN; // TIM3 clock enable } else if ((a == PB_6) && (b == PB_7)) { // pinmap OK for TIM4 CH1 and CH2 TIM = TIM4; // configure reset and clock control registers RCC->AHB1ENR |= RCC_AHB1ENR_GPIOBEN; // manually enable port B (port A enabled by mbed library) // configure general purpose I/O registers GPIOB->MODER &= ~GPIO_MODER_MODER6; // reset port B6 GPIOB->MODER |= GPIO_MODER_MODER6_1; // set alternate mode of port B6 GPIOB->PUPDR &= ~GPIO_PUPDR_PUPDR6; // reset pull-up/pull-down on port B6 GPIOB->PUPDR |= GPIO_PUPDR_PUPDR6_1; // set input as pull-down GPIOB->AFR[0] &= ~(0xF << 4*6); // reset alternate function of port B6 GPIOB->AFR[0] |= 2 << 4*6; // set alternate funtion 2 of port B6 GPIOB->MODER &= ~GPIO_MODER_MODER7; // reset port B7 GPIOB->MODER |= GPIO_MODER_MODER7_1; // set alternate mode of port B7 GPIOB->PUPDR &= ~GPIO_PUPDR_PUPDR7; // reset pull-up/pull-down on port B7 GPIOB->PUPDR |= GPIO_PUPDR_PUPDR7_1; // set input as pull-down GPIOB->AFR[0] &= ~0xF0000000; // reset alternate function of port B7 GPIOB->AFR[0] |= 2 << 4*7; // set alternate funtion 2 of port B7 // configure reset and clock control registers RCC->APB1RSTR |= RCC_APB1RSTR_TIM4RST; //reset TIM4 controller RCC->APB1RSTR &= ~RCC_APB1RSTR_TIM4RST; RCC->APB1ENR |= RCC_APB1ENR_TIM4EN; // TIM4 clock enable } else { printf("pinmap not found for peripheral\n"); } // configure general purpose timer 3 or 4 TIM->CR1 = 0x0000; // counter disable TIM->CR2 = 0x0000; // reset master mode selection TIM->SMCR = TIM_SMCR_SMS_1 | TIM_SMCR_SMS_0; // counting on both TI1 & TI2 edges TIM->CCMR1 = TIM_CCMR1_CC2S_0 | TIM_CCMR1_CC1S_0; TIM->CCMR2 = 0x0000; // reset capture mode register 2 TIM->CCER = TIM_CCER_CC2E | TIM_CCER_CC1E; TIM->CNT = 0x0000; // reset counter value TIM->ARR = 0xFFFF; // auto reload register TIM->CR1 = TIM_CR1_CEN; // counter enable } EncoderCounter::~EncoderCounter() {} /** * Resets the counter value to zero. */ void EncoderCounter::reset() { TIM->CNT = 0x0000; } /** * Resets the counter value to a given offset value. * @param offset the offset value to reset the counter to. */ void EncoderCounter::reset(short offset) { TIM->CNT = -offset; } /** * Reads the quadrature encoder counter value. * @return the quadrature encoder counter as a signed 16-bit integer value. */ short EncoderCounter::read() { return (short)(-TIM->CNT); } /** * The empty operator is a shorthand notation of the <code>read()</code> method. */ EncoderCounter::operator short() { return read(); }