2nd try
Diff: EncoderCounter.cpp
- Revision:
- 0:72b60c5271cc
diff -r 000000000000 -r 72b60c5271cc EncoderCounter.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/EncoderCounter.cpp Thu Mar 07 07:03:44 2019 +0000 @@ -0,0 +1,139 @@ +/* + * 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(); +} \ No newline at end of file