I built a remote-controlled robotics platform using a 4WD mobile platform, an Arduino (Seeeduino Mega), an Adafruit motor shield, and two XBee radios for communication. There are also some super-bright white LEDs on the front for headlights. The point of the project was to show how an XBee radio can be used to send joystick sensor data without using a microcontroller on the remote.
The vehicle is very easy to control using a joystick and a couple of buttons to control the lights. First I’ll describe how the remote control unit works, then I’ll show how the vehicle was built.
Here’s a picture of the remote control unit that I built on a breadboard. A Parallax joystick is used to control the vehicle, one button turns the headlights on/off, and another button puts the headlights in “scanner” mode, you know, like Kitt or like a cylon. The radio requires a 3.3V supply, but the analog pins cannot take more than 1.2V, so I used some precision resistors to form a voltage divider so that the analog input voltage was stepped down to less than 1.2V. Also note that the joystick is rotated 90 degrees so that it worked on a breadboard with this orientation.
For more detail: Wireless Robotics Platform with XBee Remote Control