@Crusty: So why the shaft encoder? It will not give any more information about wheel slip versus distance, or does it? and you are still going to have to count the pulses in the Arduino code.
First of all there would be three shaft encoders -- one per wheel. Depending on your motor, you can mount them on the back-end of the shaft (before the gearing) or on the output/drive shaft (after the gearing).
The main reason for having them is to provide another way to measure what the robot is actually doing compared to what it thinks it's doing. Also, there's the point that we have the three motrs, so the way they are mounted means that even if we are going "forward" (say an axis from the center directly betwen two of the wheels -- see my previous blog on this topic), a complete rotation of the wheel doesn't actually equate to the robot travelling the same distance as the circumpherance of the wheel.
Don't worry about my Arduino spending all of its time counting pulses from the encoders -- it won't be spending any time doing this -- based on Duane's current "Secret Squirrel" project, all of the boring counting stuff will be off-loaded to distributed sensor processors ... we'll be talking about this more soon...
Now there's a conundrum: how to squeal without offending Susan??
I've heard of stuck pigs being used for this purpose, but we'll probably offend the animal rights lobby....
And tyres (oops...tires) squeal as well when pushed. But they don't evoke the same sense of excitement.
So I think we're stuck with schoolgirls. Did you never squeal over your favourite pop idol, Susan? Even if you didn't, I reckon the fact that Max and Caleb squeal over Keepon gives you plenty of ammunition for having a dig at them in the future :-)
@Adam (a.k.a. Aeroengineer): Oh and did you get my email on how to solve your motor adaptor problem? I think that it will work for you. Let me know if you need any help getting that drawn up. I can help out with that.
Are you talking to me or to Duane (I haven't checked my email yet today)