TIME_STEP = 64;

% get and enable devices, e.g.:
%  camera = wb_robot_get_device('camera');
%  wb_camera_enable(camera, TIME_STEP);

while wb_robot_step(TIME_STEP) ~= -1

  % read the sensors, e.g.:
  %  rgb = wb_camera_get_image(camera);

  drawnow;

  wb_console_print( 'abcd', WB_STDOUT );

end