File content as of revision 11:39bd79605827:

#include "Encoder.h"

using namespace std;


Encoder::Encoder(PinName& hallsensor) : HallSensor(hallsensor){        
        
        TIM = TIM3;
        
        // 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
        
        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
        
        GPIOB->MODER &= ~GPIO_MODER_MODER5;     // reset port B5
        GPIOB->MODER |= GPIO_MODER_MODER5_1;    // set alternate mode of port B5
        GPIOB->PUPDR &= ~GPIO_PUPDR_PUPDR5;     // reset pull-up/pull-down on port B5
        GPIOB->PUPDR |= GPIO_PUPDR_PUPDR5_1;    // set input as pull-down
        GPIOB->AFR[0] &= ~0xF0000000;           // reset alternate function of port B5
        GPIOB->AFR[0] |= 2 << 4*5;              // set alternate funtion 2 of port B5
        
        // 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
        
        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 = 0xBF68;          // auto reload register (49000)
        TIM->PSC = 0x0003;          // divide count by 4
        TIM->CR1 = TIM_CR1_CEN;     // counter enable  
        
        // Interrupt for Origin Position
        HallSensor.fall(callback(this, &Encoder::ResetInterrupt));
        this->resetOn = 0;
        
        // Ticker for the calculation of the frequency with dt = 5ms
        this->ticker.attach(callback(this, &Encoder::calculateFrequency),dt);
           
}

Encoder::~Encoder() {
    ticker.detach();
}

uint8_t Encoder::reset() {
    static int resetted=0;
    if(this->resetOn==1){
       TIM->CNT = 49000;
       HallSensor.disable_irq();
       this->resetOn = 0;
       resetted = 1;
    }
    return resetted;
}

/**
 * Reads the quadrature encoder counter value.
 * @return the quadrature encoder counter as a signed 16-bit integer value.
 */
uint32_t Encoder::read() {
    
    return (uint16_t)49000-TIM->CNT; // Trasform Downcounter in Upcounter
}
/*
 * @return the Angle as a float value
 */
float Encoder::readAngle() {
    uint32_t pulses;
    float angle;
    
    pulses = this->read();
    angle = 2.0f * PI * pulses / 49000.0f; // 49000 Pulses per Rotation
    return angle;  
}

/*
 * @return the Frequency as a float value in rad/s
 */
float Encoder::readFrequency(){
    return frequency;    
}

/*
 * @return the Frequency as a float value in rad/s
 */
float Encoder::readAcceleration(){
    return acceleration;    
}

/*
 * @return the Frequency as a float value in rad/s
 */
float Encoder::readRPM(){
    return frequency / (2.0*PI) * 60.0;    
}

/*
 * Calculate the pedal frequency every 5ms
 */
void Encoder::calculateFrequency(){
    static float angle, angleOld = 0.0f;
    static float pedaleFreq, pedaleFreqOld = 0.0f, frequencyOld = 0.0f;
    static float accelerationOld = 0.0f;
    
    // Read actual angle
    angle = this->readAngle();
    
    // Diskrete Ableitung Frequenz
    pedaleFreq = (angle - angleOld) / dt;
   
          
    // Filter Nulldurchgang mit der Messung der Winkels und Frequenz Grenz [-2.5,2.5]rad/s
    if(((pedaleFreq - pedaleFreqOld) > 2.5) || ((pedaleFreq - pedaleFreqOld) < -2.5f) ){
    frequency = frequencyOld;
    } 
    else{
    frequency = pedaleFreq;
    }
    
    // Diskrete Ableitung Acceleration
    acceleration = (frequency - frequencyOld) / dt;
    
    // Store old value
    angleOld = angle;
    pedaleFreqOld = pedaleFreq;
    frequencyOld = frequency;
    
}

void Encoder::ResetInterrupt(){
    this->resetOn = 1;
    this->reset();
    
}
/*
 * The empty operator is a shorthand notation of the <code>read()</code> method.
 */
Encoder::operator short() {
    return readAngle();
}