in this instructable i am going to show you to how to build a android controlled car or rover .
How Does the Android-Controlled Robot Work?
The Android application controlled robot communicates via Bluetooth to the Bluetooth module present on the robot. While pressing each button on the application, corresponding commands are sent via Bluetooth to the robot. The commands that are sent are in the form of ASCII. The Arduino on the robot then checks the command received with its previously defined commands and controls the bo motors depending on the command received to cause it to move forward, backward, left, right or to stop.”