I am making a line following robot. I 've bought this line following sensor array http://probots.co.in/index.php?main_page=product_info&cPath=96_100&products_id=456 and a L293D based motor driver http://elementzonline.com/converters-interface-boards-91/dc-motor-stepper-motor-driver-board-with-l293d-ic-84. I am having problems on having connection with the arduino uno. Besides, this i have two 9V batteries to power the arduino uno and motor. Please help.
The 9V batteries look too weak for operating an stepper motor. Consider the battery capacity (mAh) and the power consumption (A) of the motor, to find out how long a battery will last.
If you cannot find libraries or example code and wirings for your devices, e.g. in the Learning section, look what devices come with detailed descriptions on their usage with an Arduino, and buy such devices.