/*
 *  spreadspace avr utils
 *
 *
 *  Copyright (C) 2013 Christian Pointner <equinox@spreadspace.org>
 *                     Othmar Gsenger <otti@wirdorange.org>
 *
 *  This file is part of spreadspace avr utils.
 *
 *  spreadspace avr utils 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
 *  any later version.
 *
 *  spreadspace avr utils 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 spreadspace avr utils. If not, see <http://www.gnu.org/licenses/>.
 */

#include <avr/sfr_defs.h>
#include <avr/interrupt.h>

#include "stepper.h"

uint8_t step_table [] = 
{
  10, // 1010
  8,  // 1000
  9,  // 1001
  1,  // 0001
  5,  // 0101
  4,  // 0100
  6,  // 0110
  2,  // 0010
};

#define STEPPER_PORT PORTF
#define STEPPER_DDR DDRF
#define STEPPER_FIRST_BIT 4
#define STEPPER_ENABLE_BIT 1
#define LENGTH_STEP_TABLE (sizeof(step_table)/sizeof(uint8_t))
#define STEPPER_OUTPUT_BITMASK (~(0xF << STEPPER_FIRST_BIT ))

volatile uint16_t step_cnt = 0;
static uint16_t step_cnt_max = LENGTH_STEP_TABLE*20;
stepper_direction_t step_direction = dir_open;

void handle_step(void)
{
  if(step_cnt < step_cnt_max)
  {
    step_cnt++;
    uint8_t stepper_output=step_table[step_cnt % LENGTH_STEP_TABLE];
    stepper_output<<=STEPPER_FIRST_BIT;
    STEPPER_PORT = (STEPPER_PORT & STEPPER_OUTPUT_BITMASK ) | stepper_output;
  } else {
    stop_stepper();
  }
}

void init_stepper(void)
{
  STEPPER_PORT &= ~(0xF << STEPPER_FIRST_BIT | 1<<STEPPER_ENABLE_BIT);
  STEPPER_DDR |= (0xF << STEPPER_FIRST_BIT) | (1<<STEPPER_ENABLE_BIT);
}

void start_stepper(stepper_direction_t direction)
{
  step_cnt = 0;
  step_direction = direction;
  STEPPER_PORT |= 1<<STEPPER_ENABLE_BIT;
  //start timer here
}

void stop_stepper(void)
{
  // stop timer here
  STEPPER_PORT &= ~(0xF << STEPPER_FIRST_BIT | 1<<STEPPER_ENABLE_BIT);
}