/*
  stepper.h - stepper motor driver: executes motion plans of planner.c using the stepper motors
  Part of Grbl

  Copyright (c) 2009-2011 Simen Svale Skogsrud
  Copyright (c) 2011 Sungeun K. Jeon

  Grbl is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  Grbl is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with Grbl.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef stepper_h
#define stepper_h 

#include <avr/io.h>

// Some useful constants
#define STEP_MASK ((1<<X_STEP_BIT)|(1<<Y_STEP_BIT)|(1<<Z_STEP_BIT)) // All step bits
#define DIRECTION_MASK ((1<<X_DIRECTION_BIT)|(1<<Y_DIRECTION_BIT)|(1<<Z_DIRECTION_BIT)) // All direction bits
#define STEPPING_MASK (STEP_MASK | DIRECTION_MASK) // All stepping-related bits (step/direction)
#define STEPPERS_DISABLE_MASK (1<<STEPPERS_DISABLE_BIT)

#define TICKS_PER_MICROSECOND (F_CPU/1000000)
#define CYCLES_PER_ACCELERATION_TICK ((TICKS_PER_MICROSECOND*1000000)/ACCELERATION_TICKS_PER_SECOND)


// Initialize and setup the stepper motor subsystem
void st_init();

// Enable steppers, but cycle does not start unless called by motion control or runtime command.
void st_wake_up();

// Immediately disables steppers
void st_go_idle();

// Reset the stepper subsystem variables       
void st_reset();
             
// Notify the stepper subsystem to start executing the g-code program in buffer.
void st_cycle_start();

// Reinitializes the buffer after a feed hold for a resume.
void st_cycle_reinitialize(); 

// Initiates a feed hold of the running program
void st_feed_hold();

#endif