qdec_example.c

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/* This file has been prepared for Doxygen automatic documentation generation. */
#include "avr_compiler.h"
#include "qdec_driver.h"
#include "qdec_signal_generator.h"

//#define GENERATE_TEST_SIGNAL

uint8_t freq = 60;

bool dir  = CW_DIR;

#define CLOCK_DIV_bm  TC_CLKSEL_DIV64_gc
#define CLOCK_DIV     64

uint8_t lineCount = 30;

uint16_t captureFreq  = 0;
uint16_t calcFreq     = 0;
uint16_t calcRPM      = 0;

int main( void )
{
        /* Set up port C as output. */
        PORTC.DIRSET = 0xFF;

        /* Setup PORTD with pin 0 as input for QDPH0, dont invert IO pins.
         *
         * Setup event channel 0, pin 0 on PORTD as input, don't enable index.
         * if index used then state 00 is set as the index reset state.
         *
         * Setup TCC0 with Event channel 0 and lineCount.
         */
        QDEC_Total_Setup(&PORTD,                    /*PORT_t * qPort*/
                         0,                         /*uint8_t qPin*/
                         false,                     /*bool invIO*/
                         0,                         /*uint8_t qEvMux*/
                         EVSYS_CHMUX_PORTD_PIN0_gc, /*EVSYS_CHMUX_t qPinInput*/
                         false,                     /*bool useIndex*/
                         EVSYS_QDIRM_00_gc,         /*EVSYS_QDIRM_t qIndexState*/
                         &TCC0,                     /*TC0_t * qTimer*/
                         TC_EVSEL_CH0_gc,           /*TC_EVSEL_t qEventChannel*/
                         lineCount);                /*uint8_t lineCount*/

        /* Setup TCD0 with Event channel 2 for same pin as QDPH0 and clk div 64. */
        QDEC_TC_Freq_Setup(&TCD0, TC_EVSEL_CH2_gc, EVSYS_CHMUX_PORTD_PIN0_gc, CLOCK_DIV_bm);

#ifdef GENERATE_TEST_SIGNAL
        /* Initialize and start outputting quadrature signal.*/
        generate_qdec_signal(&PORTE, lineCount, freq, dir);

        /* Enable low level interrupt.*/
        PMIC.CTRL |= PMIC_LOLVLEN_bm;

        /* Enable global interrupts.*/
        sei();
#endif
        
        /* Display the frequency of rotation on LEDs */
        while (1) {

                if ((TCD0.INTFLAGS & TC0_CCAIF_bm) !=  0) {
                        /* Period of counter ticks are 1/(F_CPU/clk_div)
                         * Real tick count is 4 times captured value
                         * (when used with quadratur signal).
                         * Real frequency is then (F_CPU/clk_div)/(capture_value * linecount)
                         * For output in RPM multiply frequency by 60 (60 sec per min).*/
                        calcFreq = (F_CPU / CLOCK_DIV) /
                                   ((GetCaptureValue(TCD0) & 0xFFFC) * lineCount );
                        calcRPM = calcFreq*60;
                        PORTC.OUT = ~(calcFreq);
                }
        }
}