File content as of revision 0:29fc24ce612f:

#include "mbed.h"
#include "DRV8825.h"
#define MAX_SPEED 8000
#define MICROSTEPS_PER_STEP 32
// add boundaries

//DigitalOut myled(LED1);
    int PULL = 1;
    int PUSH = 0;
    int SALT = 1;
    int PURE = 0;
    int PREVIOUS_DIRECTION_SALT = -1;
    int PREVIOUS_DIRECTION_PURE = -1;
    int POSITION_SALT = 14;
    int POSITION_PURE = 27;
    int MAX = 35;
    int MIN = 0; 
    
    DRV8825 stpr_mtr(p21, p27, p28, p29, p22, p23);
    DRV8825 stpr_mtr2(p24, p27, p28, p29, p25, p26);

void add_water(int type, int mililiters, int DIRECTION){
        
    int MOVEMENT = 1800; //constant for 1 mL
    int STEP_EXTRA = 2500; //for the other mL's
    
    if (mililiters > 0){
        if (type == SALT){
            if (DIRECTION == PULL){
                if (POSITION_SALT + mililiters >= MAX)
                    mililiters = 0;
                else   
                    POSITION_SALT = POSITION_SALT + mililiters;
            }else{    
                if (POSITION_SALT - mililiters <= MIN)
                    mililiters = 0;
                else 
                    POSITION_SALT = POSITION_SALT - mililiters;
            }    
        }else { 
            if (DIRECTION == PULL) 
                if (POSITION_PURE + mililiters >= MAX)
                    mililiters = 0;
                else 
                    POSITION_PURE = POSITION_PURE + mililiters;
            else   
                if (POSITION_PURE - mililiters <= MIN)
                     mililiters = 0;
                else  
                    POSITION_PURE = POSITION_PURE - mililiters;
        }       
            
        //accelerate
        for (int i = 25; i < MAX_SPEED; i+=20) {
            if (type == SALT)
                stpr_mtr.settings(1/MICROSTEPS_PER_STEP, DIRECTION, i);
           else 
               stpr_mtr2.settings(1/MICROSTEPS_PER_STEP, DIRECTION, i);      
        } 
    
        //fix the changing of directions for pure
        if (type == PURE){
                
            mililiters = mililiters * 2.2;    
           if (PREVIOUS_DIRECTION_PURE != DIRECTION)
              mililiters = mililiters + 1;
        }    
    
        //fix the changing of directions for salt
        if (type == SALT){ 
            
          mililiters = mililiters * 0.9;
          if (PREVIOUS_DIRECTION_PURE != DIRECTION)
             mililiters = mililiters + 1;
         //if (PREVIOUS_DIRECTION_SALT == PULL)
               //mililiters = mililiters + 0.5;      
        }    

        //move with constant speed
        for (int i = 1; i < (MOVEMENT + (mililiters - 1)*STEP_EXTRA); i+=1) {
            if (type == SALT)
                stpr_mtr.settings(1/MICROSTEPS_PER_STEP, DIRECTION, MAX_SPEED);
            else
                stpr_mtr2.settings(1/MICROSTEPS_PER_STEP, DIRECTION, MAX_SPEED);    
        }
    
        //de-accelerate
        for (int i = MAX_SPEED; i > 0; i-=20) {
            if (type == SALT)
                stpr_mtr.settings(1/MICROSTEPS_PER_STEP, DIRECTION, i);
            else
                stpr_mtr2.settings(1/MICROSTEPS_PER_STEP, DIRECTION, i);    
        }
    
        //remember previous direction
        if (type == SALT)
            PREVIOUS_DIRECTION_SALT = DIRECTION;
        else
            PREVIOUS_DIRECTION_PURE = DIRECTION;  
         wait(2);
     }        
}

int main() {
    //add_water(PURE, -1, PUSH);
    //add_water(SALT, -1, PUSH);
    
    
    add_water(SALT, 1, PULL);
    add_water(SALT, 1, PUSH);
    add_water(SALT, 2, PULL);
    add_water(SALT, 2, PUSH);
    add_water(SALT, 3, PULL);
    add_water(SALT, 3, PUSH);
    
    add_water(PURE, 1, PULL);
    add_water(PURE, 1, PUSH);
    add_water(PURE, 2, PULL);
    add_water(PURE, 2, PUSH);
    add_water(PURE, 3, PULL);
    add_water(PURE, 3, PUSH);
}