Project 3: DiscRover

The idea for this project came to me during a nap (we old people need naps). I've always wondered what sorts of useful things one could make out of those "Free Trial!" CD-ROMs, sent through the mail by AOL and other Internet providers on a seemingly daily basis. In bed, it hit me: Turn them into mini robot development platforms! They're perfect. They're plentiful, plastic (easy to drill into, glue on, and so forth), and round--they even have built-in cable passthru holes in the center! Using widely available aluminum standoffs, you could stack several layers of discs on top of each other to hold mechanics, power supplies, MCUs, sensors--the works! I was so excited; I bolted (oops...unintended robotbuilder pun) out of bed to start writing up some specs. About 10 minutes into it, something else hit me. This was way too obvious. Somebody must have already thought of this idea (because many a geek ponders the "What to do with all those dang discs?" conundrum). I stopped my sketching and did a Web search. After some creative Googling, I found the robot taxonomy I was looking for: "CDBots." Sure enough, people have used junk CDs to make similar platform robots, they've used them as wheels for bots (just add rubber band tires), and they've even hot-glued dozens of them together, fanned out into large multidisc platform levels. I was slightly crestfallen that this "big idea" wasn't mine, but glad to see that people had finally found something useful to do with the ol' plastic spam (as these snail-mail-borne discs are sometimes called). This project serves as your gateway to future experimentation, and future robots. Like any respectable robot development platform, it provides a basis for new hardware add-ons and new software controls. We'll build the mechanics for the platform, hook up our two controllers (the microcontroller unit and the motor controller), build the first sensor system, and then create our first control program (to run the motors and link motor control to sensor input). From there, we'll point you to excellent resources that show you how to add additional sensors and sensor-control software.

What's on the site:

Bug Report: Known Bugs and "Issues"
Bottom CD Template (Figure 9.5)
Top CD Template (Figure 9.9)
DiscRover1.OSC (motor control code) (Listing 9.1)
DiscRover2.OSC (final control code) (Listing 9.2)
And now, a word about Switches
Additional DiscRover Hacks:
* Improved Control Code using OOPic "Virtual Circuits"
* See an awesome video of one DiscRover builder's hack to add edge-detection to the bot.

Useful Project Links:

Solarbotics (Parts source for this project)
Jameco (Source for parts, tools and supplies)
Savage Innovations (Makers of the OOPic Microcontroller)
Programming and Customizing the OOPic Microcontroller (This "official handbook" for the OOPic came out just as my book was going to press. Tons of great stuff here and numerous ideas for expanding your DiscRover's capabilities)