These are cuteys electronics, there is a arduino mega, HC-SR04 sensor, two modified robot servos with wheels, arduino sensor shield, and wires.
Cutey is a autonomous robot with a twist, HE WANTS FRIENDS!
He will spin around until you put your hand in front of him then he will follow you, so don't put him in front of a wall.

Step 1:

The servos are connected together with a LEGO piece and hot glue, for easy mounting.

Step 2:

Right servo cable to the sensor shield digital 11, left servo cable to the sensor shield digital 10.

Step 3:

Make the wheels by hot gluing together the servo hub to the wheels.

Step 4:

HC-SR04 Trig pin to pin 52 on arduino mega and echo to 50.

Step 5:

here is the code.

#include <Servo.h>

Servo myservo;
Servo myservo2;
const int pingPin = 50;
const int pingPin2 = 52;
void setup() {
Serial.begin(9600);
      myservo.attach(10);
      myservo2.attach(11);
}

void loop()
{
long duration, inches, cm;

pinMode(pingPin2, OUTPUT);
digitalWrite(pingPin2, LOW);
delayMicroseconds(2);
digitalWrite(pingPin2, HIGH);
delayMicroseconds(5);
digitalWrite(pingPin2, LOW);

pinMode(pingPin, INPUT);
duration = pulseIn(pingPin, HIGH);

inches = microsecondsToInches(duration);
cm = microsecondsToCentimeters(duration);

if(inches < 5){
   myservo.writeMicroseconds(2000);
myservo2.writeMicroseconds(2000);
   }
if(inches > 5){
      myservo.writeMicroseconds(1000);
myservo2.writeMicroseconds(1000);
   }

Serial.print(inches);
Serial.print("in, ");
Serial.print(cm);
Serial.print("cm");
Serial.println();

delay(100);
}

long microsecondsToInches(long microseconds)
{
return microseconds / 74 / 2;
}

long microsecondsToCentimeters(long microseconds)
{
return microseconds / 29 / 2;
}