stepper.c

Go to the documentation of this file.

/***************************************************************************
***  Fraunhofer IPA 
***  Robotersysteme 
***  Projekt: 3D cartography demonstrator
****************************************************************************
****************************************************************************
***  Autor: Julio Sagardoy (goa-js)
***************************************************************************/


#include <avr/io.h>
#include <avr/interrupt.h>
#include <util/delay.h>

#include "encoder.h"
#include "stepper.h"
#include "utils.h"
#include "usart.h"

static int16_t curr_step_num = 0;               
volatile char indexSet = 0;                             
static int16_t rem_steps;
static uint8_t latency;


void stepper_set_direction( int8_t dir )
{
        if(dir >= 1)
                BITSET(PORTL,PL3);      //Rotation direcion CW
        else
                BITCLR(PORTL,PL3);      //Rotation direcion to CCW
}

int8_t stepper_get_direction()
{
        //Seen from top:
        // 1: CW
        // 0: CCW
        return BITREAD(PINL,PL3);
}

int16_t stepper_read()
{
        return curr_step_num;
}

void stepper_set( const int16_t target_pos )
{
        for(int16_t i=curr_step_num; i<target_pos; i++)
                stepper_advance();
}

void stepper_set_rem_steps( const int16_t steps)
{
        rem_steps = steps;
}
int16_t stepper_get_rem_steps()
{
        return rem_steps;
}
void stepper_set_latency( const uint8_t lat)
{
        latency = lat;
}
uint8_t stepper_get_latency()
{
        return latency;
}
        
void stepper_advance()
{
        BITCLR(PORTL,PL0);      
        _delay_us(900); // Hold line down to advance one step
        BITSET(PORTL,PL0);
        
        // check direction to update step counter
        if( stepper_get_direction() )
                curr_step_num++ ;
        else
                curr_step_num-- ;
}

void stepper_cal()
{
        //Rotate pan CCW till index is found
        indexSet = 0;
        stepper_set_direction(0);

        while( !indexSet )
        {
                _delay_ms(15);          // 20 ms interstep is really slow, but securs no extra step after index is passed
                stepper_advance();      // comand single step advance
        }
        
        stepper_set_direction(1);       // change direciton of rotation and some steps (this is to avoid having to manually reposition again when recalibrating to avoid)
        for(int8_t i=0; i<4; i++)
        {       
                _delay_ms(15);          // 20 ms interstep is really slow, but securs no extra step after index is passed
                stepper_advance();
        }
        
        _delay_ms(100);         // delay to let motor settle
        indexSet = 0;           // reset index flag
        curr_step_num = 0;      // reset step count
        encoder_reset();        // reset encoder counter

        uart_puts("L");         // from now on, the platform is calibrated. Notify host:
}

ISR(PCINT0_vect)
{
        indexSet = 1;
}

void stepper_init()
{
        DDRL = 0x6F;            // set pin direction

        // Set stepper "configuration"
        BITSET(PORTL,PL0);              // keep clk high. 
        BITSET(PORTL,PL5);              // reset counter, drive down for a clk cycle
        BITSET(PORTL,PL1);              // step type.
                                                        // | Full step | Low  |
                                                        // | Half step | High |
                                                        
        BITSET(PORTL,PL2);              // chopper controls __ lines:
                                                        // | ABCD | High |
                                                        // | INH  | Low  |

        BITSET(PORTL,PL4);              // enable pull-up for HOME pin of L297
        BITSET(PORTL,PL5);              // reset counter, drive down for a clk cycle
        BITSET(PORTL,PL6);              // enable ic
}