Colony » Colony Scout » Colony Scout OS

extern "C"

{

#include <avr/io.h>

#include <util/delay.h>

}

#include "stepper.h"

/*  Stepper Motor:

 *  Provides interface to stepper motor.

 *  Can set direction. Outputs pulse to stepper upon call of step func

 *  Also provides variable speed sweep

 */

struct step_t {

  int pos; // position in rotation.

  int dir; // direction. -1 CCW. 1 CW. 0 OFF

  int step_size; // amount to add to position each step

  int ccw;

  int cw;

} step;

void step_init()

{

  /* init pos and dir to 0 */

  step.pos = 0;

  step.dir = 0;

  //set control pins as output

  DDRD |= ((1<<S_STEP) | (1<<S_DIR));

  DDRB |= ((1<<S_MS));

  //initiate to full steps

  step_set_size(STEP_WHOLE);

  //initiate the step pin to be low. stepper steps on low to high

  PORTD &= (~(1<<S_STEP));

}

void step_set_size(char size)

{

  if (size == STEP_WHOLE)

  {

    PORTB &= ~_BV(S_MS);

    step.step_size = 2;

  }

  else

  {

    PORTB |= _BV(S_MS);

    step.step_size = 1;

  }

}

/* set direction pin */

void step_dir(int dir)

{

  step.dir = dir;

  switch(dir)

  {

    case 1:

      PORTD |= (1<<S_DIR);

      break;

    case -1:

      PORTD &= (~(1<<S_DIR));

      break;

  }

}

void step_do_step()

{

  if(step.dir==0) return; //do not step if not enabled

  PORTD |= (1<<S_STEP); //step once 

  _delay_us(1); //conform with step timing

  PORTD &= (~(1<<S_STEP)); //bring the step bin back down

  if(step.dir==1) step.pos += step.step_size;

  else step.pos -= step.step_size;

}

void step_flush()

{

  PORTD &= (~(1<<S_STEP)); //bring the step bin back down

}

//ccw must be less than 0 and cw must be greater than 0

void step_sweep_bounds(int ccw, int cw)

{

  step.ccw = ccw;

  step.cw = cw;

}

void step_sweep()

{

  step_do_step();

  if((step.dir == 1) && (step.cw <= step.pos)) step_dir(-1);

  else if((step.dir == -1) && (step.ccw >= step.pos)) step_dir(1);

}