View Full Version : [Contest Entry] Hexabot 6x6 tabletop Robot

09-19-2007, 11:09 PM
Hello everyone,

Here is a bot I created for a contest that the Chicago Area Robotics club held last year. The robot is called Hexabot.


It has 6 motors directly driving 6 wheels. With the exception of the electronics, it is constructed entirely of Tamiya parts:
Motors: 6 High Speed Gearboxes H.E.
Tires: 6 Sports Tires
Main Body: 3 Universal Plates connected with long universal arms
Underside Support: Long universal arms
Battery: Tenergy 7.4v 800mAH high output Li-Poly
Motor Controller: Pololu VNH3SP30 dual h-bridge
Main Controller: DevBoard-M32
The contest is listed here - http://www.chibots.org/drupal/?q=node/27

Here is a video of Hexabot doing a test run:

It's able to complete the course in less than 3 seconds.

Then, just for fun, I added a Madcatz wireless PS2 controller. The PS2 uses SPI to communicate between the joystick and the game console. I wired the receiver to the DevBoard-M32 and can receive and decode all the buttons and joysticks.


Here is a video of me running it around my family room:


My plan is to have it ready to compete in the line following contests at the Fall Chibotica games being held during iHobby Expo.

Eddy Wright
Wright Hobbies Robotics

09-21-2007, 12:01 PM
I have some questions, if you don't mind. Was interfacing the Play Station controller to your dev board is pretty straightforward? Is the command set published somewhere?

Also, what kind of ISP cable do you use? I've been looking at USB programmers, but they're kind of pricy.

[edit:] Thanks for submitting your project! It's entered in this month's contest.

09-21-2007, 01:08 PM
Hi Dave,

It took a while to do the research and tweak the timing but once that was done the rest wasn't too hard.

I have attached the Bascom code I use for Hexabot and the PS2 pinouts. I also show how to make the joysticks non-linear to manage the sensitivity of the small wireless joysticks.

Communications with the PS2 joystick is handled by the SPI port. Take a look at the Config SPI statement in the code and look at the PS2 subroutine. If you are familiar with SPI, you know that sometimes data is sent and received at the same time. I had to use a combination of SPIOUT (sends a byte) and SPIMOVE (sends a byte and receives a byte simultaneously).

As for a USB programmer, I haven't seen a lot of affordable choices. Pololu has one for $27, the best price so far. It has a 6-pin header on it but I have 6-pin to 10-pin adapters to make it work with my stuff. If you have a PC, your bet bet may be to add in a Parallel/Serial I/O card and wait on USB. The cost of a USB programmer and a USB to Serial adapter will add up.


09-24-2007, 04:58 PM

You may be able to use a key mapper (some USB game pads come with the software for it).

Check out Wal*Mart.