void do_step(byte step_pin, byte dir_pin, byte dir)
{
        if (dir)
        {
         //Serial.println("+");
            if (digitalRead(step_pin) == HIGH) {
                if (digitalRead(dir_pin) == HIGH) {
                     digitalWrite(step_pin, HIGH);
                     digitalWrite(dir_pin, LOW);
                }
                else {
                     digitalWrite(step_pin, LOW);
                     digitalWrite(dir_pin, LOW);          
                }             
            }
            else {
                if (digitalRead(dir_pin) == HIGH) {
                     digitalWrite(step_pin, HIGH);
                     digitalWrite(dir_pin, HIGH);
                }
                else {
                     digitalWrite(step_pin, LOW);
                     digitalWrite(dir_pin, HIGH);
                }    
            }
        }
     else
        {
         //Serial.println("-");
            if (digitalRead(step_pin) == HIGH) {
                if (digitalRead(dir_pin) == HIGH) {
                     digitalWrite(step_pin, LOW);
                     digitalWrite(dir_pin, HIGH);
                }
                else {
                     digitalWrite(step_pin, HIGH);
                     digitalWrite(dir_pin, HIGH);            
                }             
            }
            else {
                if (digitalRead(dir_pin) == HIGH) {
                     digitalWrite(step_pin, LOW);
                     digitalWrite(dir_pin, LOW);
                }
                else {
                     digitalWrite(step_pin, HIGH);
                     digitalWrite(dir_pin, LOW);
                }    
            }
        }

     //digitalWrite(step_pin, HIGH);
     delayMicroseconds(5);
     //digitalWrite(step_pin, LOW);
}