This is a great little autonomous robot project using an arduino that can easily be completed in a short amount of time. We used a Modern Device RBBB (Really Bare Bones Board) as the brain of our robot. These RBBB kits are also great if you are new to soldering. Not a lot of parts, but just enough to get get some experience with.
The robot is powered with four AA batteries. The biggest cost expense with the project would be for the servos – (2) continuous rotation servos and (1) standard servo. For the eyes we used a Sharp IR Sensor.
The robot sweeps the ir range finder 130 degrees and records the closest object. Objects closer than 10 inches will cause the robot to take action. If this object is more than 45 degrees to the right or left it makes a small correction away from the object. If the object is within the center 90 degrees, it stops, looks left and right, finds the clearest direction and turns about 90 degrees to that direction.