Adafruit Motor Shield MATLAB GUI

Hi all,

This is my first post.

I am currently building an xy gantry as a part of a project. I am using an Arduino Uno, an Adafruit Motor Shield, and 2 stepper motors. I have interfaced the Arduino with a MATLAB GUI and the connection is working great but what I am finding is that as I run the program I created I cannot run the 2 motors simultaneously. One axis moves the required steps and then once its finished the second moves. Its simple code but surely it should work?

function BeginButton_Callback(hObject, eventdata, handles)
% hObject    handle to BeginButton (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
global a;

    a.stepperSpeed(1, 1);
    a.stepperSpeed(2, 1);
    a.stepperStep(1, 'backward', 'double',255);
    a.stepperStep(2, 'forward', 'double', 255);

I've seen a cnc build on the arduino website where they speak of using a motor shield and sparkfun easy driver to drive the 3 motors but cannot get it to work myself.

http://blog.arduino.cc/category/languages/mathlab/

Can anyone help me out on this one?

Thanks,

Colm