Using the extra base section cut at the beginning you can add a servo and sonar device for greater ranging abilities.
You will need:
Servo (not modified)
SRF04 or 08 with servo mount from Acroname (www.acroname.com)
Spare base section
Cut a hole in the front edge of the plywood just large enough for the servo to fit into.
Install plywood over the long standoffs and secure with some 4-40 nuts. You will need to countersink the bottom side of the holes to allow the entire standoff diameter to fit in them about 1/8 inch so that the threads stick up far enough.
Install the servo, sonar mount and sonar.
Hook the servo to oopic servo port 29 and wire the sonar to the pins as shown in the oopic users manual. You will have to use the sample code in the IDE to test it as I have not written any yet... Battery died.
You can add many levels for add ons if you want simply by cutting and drilling more pieces of plywood and adding standoffs.
Add more sensors like the QRB1134 to make your bot a line follower.
Have fun and build more bots! You can email me on or off list for help.
I will add video shortly. I am on dialup and have to drive 20 miles to town to get to high speed.