encoder.cpp

#include <Arduino.h>
#include "encoder.h"
#include "config.h"

//REG_TC0_CV0 Stores count from encoder
//REG_TC0_CV1 Stores count from index if interrupts are off

volatile int z_Total=0;

void setup_encoder()
{
    // Setup Quadrature Encoder with Marker
    REG_PMC_PCER0 = (1<<27); // activate clock for TC0
    REG_PMC_PCER0 = (1<<28); // activate clock for TC1

    // select XC0 as clock source and set capture mode
    REG_TC0_CMR0 = (1<<0)|(1<<2)|(1<<8)|(1<<10);
    REG_TC0_CMR1 = 0;

    // activate quadrature encoder and position measure mode, filter short pulses
    REG_TC0_BMR = (1<<8)|(1<<9)|(1<<12)|(60 << 20);
    
    // enable the clock (CLKEN=1) and reset the counter (SWTRG=1)
    REG_TC0_CCR0 = 5;
    REG_TC0_CCR1 = 5;
    
    REG_TC0_IDR1=0b11111111; // disable all interrupts for TC0

    //Remark out the next 4 lines to remove index interrupt and
    // accumulate index count
    REG_TC0_CMR1 = (1<<8); // Set rising edge of Z
    REG_TC0_IER1=0b10000000; // enable interrupt on Z
    REG_TC0_IDR1=0b01111111; // disable other interrupts
    NVIC_EnableIRQ(TC1_IRQn);
}

int getEncoderCount()
{
    int value = REG_TC0_CV0;
    return value;
}

int getEncoderRevs()
{
    int value = REG_TC0_CV1;
    return value;    
}

void TC1_Handler() {
    z_Total = REG_TC0_CV1;
    long dummy=REG_TC0_SR1; // vital - reading this clears the interrupt flag
    //controllerStatus.theta = 255;
}