arduino_simultaneous_stepper_driver.ino

/**
 * Drive a collection of stepper motors, 1 step at a time in sequence, a desired number of steps.
 * Used to approximate simultaneous motion of each stepper by not blocking until motion is completed.
 * 
 * steppers = Array of Stepper library stepper motors.
 * numSteppers = length of steppers array.
 * numStepsMap = number of total steps to advance by. Positve number moves forward. Negative number moves backward.
 */
void simultaneousStepperDrive(Stepper steppers[], int numSteppers, int numStepsMap[]) {
  int stepsExecuted = 0;
  int numSteps,
      numStepsAbs;
  while(true) {
    bool stepsRemaining = false;
    for(int i=0; i < numSteppers; i++) {
      numSteps = numStepsMap[i];
      numStepsAbs = abs(numSteps);

      if(numStepsAbs > stepsExecuted) {
        steppers[i].step(numSteps/numStepsAbs); //  One step in desired direction

        //  Determine if we're done after this step or not. If not, indicate steps remaining.
        if((numStepsAbs - stepsExecuted -1) > 0) {
          stepsRemaining = true;
        }
      }
    }


    if(!stepsRemaining) {
      break;
    }

    stepsExecuted++;
  }
}