BA
Backup 1
Diff: EncoderCounter.cpp
- Revision:
- 0:02dd72d1d465
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/EncoderCounter.cpp Tue Apr 24 11:45:18 2018 +0000
@@ -0,0 +1,169 @@
+/*
+ * EncoderCounter.cpp
+ * Copyright (c) 2018, 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_1) && (b == PA_0)) {
+
+ // pinmap OK for TIM2 CH1 and CH2
+
+ TIM = TIM2;
+
+ // configure general purpose I/O registers
+
+ GPIOA->MODER &= ~GPIO_MODER_MODER0; // reset port A0
+ GPIOA->MODER |= GPIO_MODER_MODER0_1; // set alternate mode of port A0
+ GPIOA->PUPDR &= ~GPIO_PUPDR_PUPDR0; // reset pull-up/pull-down on port A0
+ GPIOA->PUPDR |= GPIO_PUPDR_PUPDR0_1; // set input as pull-down
+ GPIOA->AFR[0] &= ~(0xF << 4*0); // reset alternate function of port A0
+ GPIOA->AFR[0] |= 1 << 4*0; // set alternate funtion 1 of port A0
+
+ GPIOA->MODER &= ~GPIO_MODER_MODER1; // reset port A1
+ GPIOA->MODER |= GPIO_MODER_MODER1_1; // set alternate mode of port A1
+ GPIOA->PUPDR &= ~GPIO_PUPDR_PUPDR1; // reset pull-up/pull-down on port A1
+ GPIOA->PUPDR |= GPIO_PUPDR_PUPDR1_1; // set input as pull-down
+ GPIOA->AFR[0] &= ~(0xF << 4*1); // reset alternate function of port A1
+ GPIOA->AFR[0] |= 1 << 4*1; // set alternate funtion 1 of port A1
+
+ // configure reset and clock control registers
+
+ RCC->APB1RSTR |= RCC_APB1RSTR_TIM2RST; //reset TIM2 controller
+ RCC->APB1RSTR &= ~RCC_APB1RSTR_TIM2RST;
+
+ RCC->APB1ENR |= RCC_APB1ENR_TIM2EN; // TIM2 clock enable
+
+ } else 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(int16_t offset) {
+
+ TIM->CNT = -offset;
+}
+
+/**
+ * Reads the quadrature encoder counter value.
+ * @return the quadrature encoder counter as a signed 16-bit integer value.
+ */
+int16_t EncoderCounter::read() {
+
+ return static_cast<int16_t>(-TIM->CNT);
+}
+
+/**
+ * The empty operator is a shorthand notation of the <code>read()</code> method.
+ */
+EncoderCounter::operator int16_t() {
+
+ return read();
+}
+