Djeff-209 is my first robot, based on the LMR Start Here robot.
I swapped out the wheels for tracks, and an SRF05 ultrasonic in place of the Sharp IR sensor.
At first, Djeff would try to avoid invisible objects, so I simply added an additional range check before initiating collision avoidance (I was getting "ghost returns" from the SRF05).
Articles (and code) I used to get off the ground:
My code is attached.