Dan Michaels wrote:

> >When will they be ready?? :o)
>
> Soon as I finish designing/prototyping the IR and ultrasonic
> transceiver ckts, and finish the pcb layout and get some
> protos :).
>
> Analog pickup amps --> LM324, 2 each 2-stage, single-supply,
> ac-coupled, inverter followed by non-inverter, gain selectable
> by R values, designed to handle any of phototransistor,
> electret mike, or ultrasonic rcvr. Pretty much std ckt.
> Any specific suggestions here?

I almost always use some type of RC filter etc before
any opamp, maybe a couple of stages. I suppose a few pads
there to patch in R,C,L etc without having to cut tracks??


>
> Separate IR LED / optologic detector [QSE156QT] channel.

Cool.

>
> External switch pickups - 4-6 stage R-ladder --> A/D channel [not
> real-time INTs like Tom's, but with programmable timer T0 or T1
> can perform A/D readings on fast basis].

Again cool.

>
> BTW, do you think having 2 ea L293's on board will satisfy your
> basic motor requirements? [I know you would really like 2-5Amps].
> There are some larger current pin-compat drivers, eg SN754410,
> that could be used with external clamp diodes.

For small stepper bots (ie micromouse competition) the
normal steppers are about 100mA to 400mA per motor, so that's
fine. Being able to drive a 1A motor (two 0.5A coils per motor
with small heatsinking will allow a pretty tough bot. My bot
pushes 1kg and uses 200mA total per motor. DC motors similar,
most micromouse dc motor/gearbox are under 500mA on average.

>
> Trying to keep small form-factor, so ....... [I think it will
> all fit].


Since the price of your SBC was quite reasonable, I am sure
you could sell half-kits (board, PIC, L293 etc) to schools
and colleges for micromouse competition. Having one board
that does the lot makes it more a programming exercise than
a major construction one.

Might I suggest the ability to measure battery voltage?
Two little resistors on-board would be nice! ;o)
-Roman

PS. Maybe you sponsoring a mouse competition might
be cool??

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