Schematic and Code for Line Tracing mode
https://github.com/layadcircuits/linetracing_mobotshield

Schematic and Code for sumobot mode.

Example 1 uses an IR distance sensor and ultrasonic for enemy sensing
https://github.com/layadcircuits/Sumobot_example_no1

Example 2 uses ultrasonic only
https://github.com/layadcircuits/sumobot_example_no2

Schematic And Code for Obstacle Avoidance robot
https://github.com/layadcircuits/Obstacle-Avoidance-Robot

Schematic and Code for Object Follower Robot
https://github.com/layadcircuits/object_follower

Assembly of Wheels:
Watch 2:40 to 5:00 of https://www.youtube.com/watch?v=eKcKdMb_nkQ

Kimat Mobot Shield Userguide:
http://layadcircuits.com/ds/Kimat-Mobot-Shield/LayadCircuits_Kimat_Mobot_Shield_UG_v2.pdf