Wheel Robot with Ranging Sensor

Do you usually take a walk in the morning with your dog beside you? Do you want something cool? What about a robot follow behind you?

This is a project about Robot that have four wheel (4WD) that have capability to response based on ultrasonic ranging sensor.

That main parts of the robot are:
1. Wheel, motor and chasis, taken from 2 Tamiya toys
2. Robot controller based on microcontroller AT89S52
3. Parallax PING ultrasonic ranging sensor
4. Stepper motor to rotate "the ultrasonic eye"
5. Stepper motor driver based on 2803A
6. DC motor driver based on L293

Robot will try to find object in 30 cm. The robot then will follow (keep the 30 cm distance) to the first object found. So if I give my hand close to the robot than it will move based on the position of my hand (as long as I move my hand slowly).

The program done by assembly language.