I'd like to introduce the newest addition to the WiMo family, WiMonet (prounounced Wee-Monay). 

 

WiMonet is a 2 wheeled robot that has the ability to draw on a whiteboard using a dry-erase marker.  WiMonet will make his debut at MEDC 2007, so come on by and have WiMonet draw something for you :). 

This robot is hot off the assembly line, so there is still some work to be done.  There are a few hardware tweaks I want to make as well as the software to get him drawing on his own.  Currently I can manually drive him like the previous WiMos.  Check out the first picture drawn by WiMonet:

WiMonet is learning to be quite the artist.  He is currently in his abstract phase :)

I need to center the pen a bit better, but that shouldn't be too big of a task.  The circle toward the center at the bottom (with the diagonal line) is the result of WiMonet dancing the hokey pokey :).

What's new in WiMonet?

Similar to the Aggressor model, WiMonet uses a OOPic microcontroller and BlueSmirf Bluetooth module for the low-level brain and a Windows Mobile Smartphone as the main brain on board.  WiMonet also adds the following new features:

  • Longer battery life:  This was a must.  That little 9v battery I was using didn't last very long mainly because it was powering the servo that turned the smartphone, and because 9v batteries only hold about 850mAh of juice (compared to the 2,000+ mAh of a AA)
  • 360 degree turning servo:  Now WiMo's head can turn all the way around.  The Aggressor model used a standard servo which could only turn about 180 degrees.  The servo i'm using now has a custom made (via BudgetRobotics) gear that allows it to turn a bit more than 360 degrees using a common servo.
  • Wheel Encoders:  I went with very basic Wheel encoders here.  These only measure how much the wheel has moved, not the direction.  But either way, this gives WiMonet the ability to programatically go specific distances (as well as keep track of those distances).
  • Digital Compass: While not as accurate as I have dreamed (although i'm still getting the hang of it) this compass was pretty easy (was recommended) and one of the cheapest i could find ($52).  This will give WiMonet a sense of direction.

WiMonet kept the ever-rugged rubberbands and even added a clothespin, although it's the more expensive plastic kind which you can get at Target for $4 for a pack of 25 :)

I'm planning on having a tutorial as well as an update to the source code in a couple of weeks so that you can build your own.  I think it's time for me to go learn Logo ;)

Hope to see you at MEDC!

  -- Brian