[Yaaarc] Tabletop Foam/Rubberband Warbots

[Keith Mc. (Route-To YAR)]

(Moved from thread "ThinkGeek Robotic Christmas Items". 
...Recap references follow...)
> > USB Missile Launcher $39.95 (Now THESE are cool...)
> > - http://www.thinkgeek.com/geektoys/warfare/86b8/
> > USB Rocket Launcher $39.95
> > - http://www.thinkgeek.com/geektoys/warfare/8a0f/
> > - http://www.cyberguys.com/templates/searchdetail.asp?productID=13430
> [How about a hack to allow them to be run from Janbot/Flutterbot et al,
> and have a battle?]

Erik Kauppi <ekauppi at corsa-inst.com> wrote:
> Yes it is a fun idea.
> Hard to do with a PIC or Atmel though.  They can be USB devices easily 
> enough but it's a lot tougher to be a USB host.  On the other hand 
> if we could find the right connections inside the rocket launcher 
> we could bypass the USB mess.

The latter was my thought.  Heck... I wasn't going to even bother 
TRYING to emulate a USB host.  Just open it up, and cut/tap into 
the trigger transistors with MPU logic signals.  After all, it's 
already set up to be run from 5VDC power, so the solonoids (and 
their drivers) all OUGHT to be easily interfacable.

The only hitch would be everything (including the power transistors)
were all contained within a single custom chip.  In that case, we 
just hack out ALL of the electronics, and drive the coils directly 
with transistors (or optos), kickback diodes, and a few resistors.  
(I can draw this up.) That'd allow it to be driven directly from
[flutter/jan/vex/boe-bot]'s MPU logic signal(s).

Not sure if the alt-el is manually aimed or under USB as well. 
If the latter we either hack their controls too, or mount the
gun part onto a pair of standard servos. That DEFINITELY could be 
easily run from a Janbot or Vex.

Either way, I think a Janbot or flutterbot armed with Nerf-style 
foam missles would make a truly GREAT hack... <grin>

> Remember the Open Source Robot Platform that was shown a few 
> meetings ago [with the paintball gun and camera mount]?

Very cool too, but IMHO that's the wrong scale.  My intent here was 
more "breadbox" or "handheld" scale...   IOW, tabletop warfare
vs floor or outdoor warfare.   Besides, I feel we have a better 
shot at getting competitors if we can keep it simple.

I also still feel a simple homebrew rubber band gun tripped by a 
servo would make a cool alternative to the USB Rocket Launcher.
(Even a servo horn tripping a clothspin based rubber band shooter is fine!)

Either way, here's my thoughts...

Each bot holds up a target switch at some known height, with a 
(555/software) modulated LED in the middle of it as an ID.  
Each bot needs a basic 2 (or 3) cell tracker hardware/software
combo to find the LED, and turns your bot to face it.  (I *think*
this can be made for a couple of bucks.  A simple design would
make a good topic for discussion.)

You then use a distance sensor of some kind (Maxbotix/Devanteck/Vex sonar,
Sharp IR, etc) and use a table lookup to determine gun elevation.  
Cheaper: you preset the gun for "point-blank", run toward your opponent 
until you bump into it, and fire! <GRIN>

Whenever your target is hit, the LED is turned off and the robot stops.
This allows an attacher with more than one shot to start searching 
for other opponents.  (Target design is another good topic. It must
be cheap & light. It must also be sensitive to hits, yet won't false 
trigger from its own mass when you move.)

Voila! Vextank/Jantank warfare! <GRIN>  Point values for various tasks 
accomplished is TBD.

To debug at home: Simply make a (xxKHz TBD) 555 flashing LED circuit.
Mount it in a 3x5 card, and put it on a stick at the right height 
to act as your test target.  

If people like this idea, a "test target build session" might also
make an interesting future meeting topic.

Comments?   

Remember, there's no rush. A lot of us have the FIRST build season 
coming up (in two weeks! Yikes!), so there's plenty of time to mull 
it over, discuss it online, tinker at meetings (et al), and come up 
with some sort of SIMPLE game for next spring or summer.

- Keith Mc.