Assembly

1-Connect the sensor shield to the motor driver by using 6 pin cables.

2-Connect the arduino Uno board to the sensor shield using the pin on the top of the arduino Uno and the pins on the bottom of the sensor shield.

3-Connect te two wires of the each DC motors to the sensor shield by respecting the polarities

4-Connect one wire of the switcher to the motor driver board, and then connect the second wire to one of the wire of the battery pack, the second wire of the battery pack should be connected to the motor driver too

5-Put each DC motors on each side of the chassis and maintain that with T-brackets and screw.

6-Attach to each extern sides of the DC motors the yellow wheels

7-Attach the caster wheel at the bottom of the chassis using screw too

8-Attach the motor driver, the arduino Uno board+sensor shield and the battery pack using double tap paper at the top of the chassis.

9-Program your code on arduino cc and upload that in your arduino Uno board