[chbot] Stepper Motors for Micromouse

[Richard Jones]

Hi Chris,

Many thanks for the offer of stepper motors.

Matched pairs, small enough to fit in a micromouse, and enough steps and 
power to go at a reasonable rate with the precision to stay precisely on 
course is what we need. The maze has 180mm cells. Ideally the mouse 
would be <100mm wide so that it can travel diagonally which leaves me 
with 50mm or less for each back to back motor and shaft. I'm assuming 
that I'll have to design and make wheels and tyres to suit. If thats not 
enough constraints if we found sufficient motors of similar design then 
we could have several mice in the club.

I can design the interface to suit unipolar or bipolar, any experience 
you have with this could be useful. So far H bridges using chopping and 
the inductance of the motor for current limit seem like a good idea. 
I'll probably need at least part bipolar as my CPU is 3.3V, probably not 
enough to saturate an n channel mosfet. I can choose the chop frequency 
to suit.

Maybe I could meet up with you to see what you have? My phone # at work 
is 357 0712 and home is 337 5337.

Cheers

Richard