stepper.c

/* -----------------------------------------------------------------------------
 * File:            stepper.c
 * Project:         Stepper Motor Example using timer
 * Author:          Leandro Schwarz
 * Last modified:   29/08/2014
 * -------------------------------------------------------------------------- */

// System definitions
#define F_CPU   16000000UL
#define MCU_8_BITS

// Header files
#include "LS_defines.h"
#include "LS_ATmega328.h"

// Project definitions
#define STEPPER_PHASE1_DDR  DDRB
#define STEPPER_PHASE1_PORT PORTB
#define STEPPER_PHASE1_BIT  PB0
#define STEPPER_PHASE2_DDR  DDRB
#define STEPPER_PHASE2_PORT PORTB
#define STEPPER_PHASE2_BIT  PB1
#define STEPPER_PHASE3_DDR  DDRB
#define STEPPER_PHASE3_PORT PORTB
#define STEPPER_PHASE3_BIT  PB2
#define STEPPER_PHASE4_DDR  DDRB
#define STEPPER_PHASE4_PORT PORTB
#define STEPPER_PHASE4_BIT  PB3

// Function declaration
void stepperMove(void);

// Global variables
volatile uint8 stepperPosition = 0;

// main function
int main()
{
    // Port configuration
    setBit(STEPPER_PHASE1_DDR, STEPPER_PHASE1_BIT);
    setBit(STEPPER_PHASE2_DDR, STEPPER_PHASE2_BIT);
    setBit(STEPPER_PHASE3_DDR, STEPPER_PHASE3_BIT);
    setBit(STEPPER_PHASE4_DDR, STEPPER_PHASE4_BIT);

    // Timer0 configuration
    timer0ClockPrescaller1024();
    timer0CTCMode();
    timer0OC0AOff();
    timer0OC0BOff();
    timer0ActivateCompareAInterrupt();
    timer0SetCompareAValue(155);
    sei();

    while(1){
    }
    return 0;
}

ISR(TIMER0_COMPA_vect)
{
    stepperMove();
    stepperPosition = (stepperPosition == 3)?0:(stepperPosition + 1);
    return;
}

void stepperMove(void)
{
    switch(stepperPosition){
    case 0:
        setBit(STEPPER_PHASE1_PORT, STEPPER_PHASE1_BIT);
        clrBit(STEPPER_PHASE2_PORT, STEPPER_PHASE2_BIT);
        clrBit(STEPPER_PHASE3_PORT, STEPPER_PHASE3_BIT);
        clrBit(STEPPER_PHASE4_PORT, STEPPER_PHASE4_BIT);
        break;
    case 1:
        clrBit(STEPPER_PHASE1_PORT, STEPPER_PHASE1_BIT);
        setBit(STEPPER_PHASE2_PORT, STEPPER_PHASE2_BIT);
        clrBit(STEPPER_PHASE3_PORT, STEPPER_PHASE3_BIT);
        clrBit(STEPPER_PHASE4_PORT, STEPPER_PHASE4_BIT);
        break;
    case 2:
        clrBit(STEPPER_PHASE1_PORT, STEPPER_PHASE1_BIT);
        clrBit(STEPPER_PHASE2_PORT, STEPPER_PHASE2_BIT);
        setBit(STEPPER_PHASE3_PORT, STEPPER_PHASE3_BIT);
        clrBit(STEPPER_PHASE4_PORT, STEPPER_PHASE4_BIT);
        break;
    case 3:
        clrBit(STEPPER_PHASE1_PORT, STEPPER_PHASE1_BIT);
        clrBit(STEPPER_PHASE2_PORT, STEPPER_PHASE2_BIT);
        clrBit(STEPPER_PHASE3_PORT, STEPPER_PHASE3_BIT);
        setBit(STEPPER_PHASE4_PORT, STEPPER_PHASE4_BIT);
        break;
    default:
        clrBit(STEPPER_PHASE1_PORT, STEPPER_PHASE1_BIT);
        clrBit(STEPPER_PHASE2_PORT, STEPPER_PHASE2_BIT);
        clrBit(STEPPER_PHASE3_PORT, STEPPER_PHASE3_BIT);
        clrBit(STEPPER_PHASE4_PORT, STEPPER_PHASE4_BIT);
        break;
    }
    return;
}